License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 08:07:57 -06:00
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// SPDX-License-Identifier: GPL-2.0
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2005-04-16 16:20:36 -06:00
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/*
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* IPVS An implementation of the IP virtual server support for the
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* LINUX operating system. IPVS is now implemented as a module
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* over the NetFilter framework. IPVS can be used to build a
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* high-performance and highly available server based on a
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* cluster of servers.
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*
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2010-11-19 06:25:14 -07:00
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* Version 1, is capable of handling both version 0 and 1 messages.
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* Version 0 is the plain old format.
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* Note Version 0 receivers will just drop Ver 1 messages.
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* Version 1 is capable of handle IPv6, Persistence data,
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* time-outs, and firewall marks.
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* In ver.1 "ip_vs_sync_conn_options" will be sent in netw. order.
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* Ver. 0 can be turned on by sysctl -w net.ipv4.vs.sync_version=0
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*
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* Definitions Message: is a complete datagram
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* Sync_conn: is a part of a Message
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* Param Data is an option to a Sync_conn.
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*
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2005-04-16 16:20:36 -06:00
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* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
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*
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* ip_vs_sync: sync connection info from master load balancer to backups
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* through multicast
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*
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* Changes:
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* Alexandre Cassen : Added master & backup support at a time.
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* Alexandre Cassen : Added SyncID support for incoming sync
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* messages filtering.
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* Justin Ossevoort : Fix endian problem on sync message size.
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2010-11-19 06:25:14 -07:00
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* Hans Schillstrom : Added Version 1: i.e. IPv6,
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* Persistence support, fwmark and time-out.
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2005-04-16 16:20:36 -06:00
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*/
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2009-07-30 15:29:44 -06:00
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#define KMSG_COMPONENT "IPVS"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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2005-04-16 16:20:36 -06:00
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#include <linux/module.h>
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#include <linux/slab.h>
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2005-12-26 21:43:12 -07:00
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#include <linux/inetdevice.h>
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2005-04-16 16:20:36 -06:00
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#include <linux/net.h>
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#include <linux/completion.h>
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#include <linux/delay.h>
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#include <linux/skbuff.h>
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#include <linux/in.h>
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#include <linux/igmp.h> /* for ip_mc_join_group */
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2005-12-26 21:43:12 -07:00
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#include <linux/udp.h>
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2008-07-16 05:13:43 -06:00
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#include <linux/err.h>
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2008-07-16 05:13:50 -06:00
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#include <linux/kthread.h>
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2008-07-16 05:13:56 -06:00
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#include <linux/wait.h>
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2008-09-19 12:41:56 -06:00
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#include <linux/kernel.h>
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ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
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#include <linux/sched/signal.h>
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2005-04-16 16:20:36 -06:00
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2010-11-19 06:25:12 -07:00
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#include <asm/unaligned.h> /* Used for ntoh_seq and hton_seq */
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2005-04-16 16:20:36 -06:00
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#include <net/ip.h>
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#include <net/sock.h>
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#include <net/ip_vs.h>
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#define IP_VS_SYNC_GROUP 0xe0000051 /* multicast addr - 224.0.0.81 */
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#define IP_VS_SYNC_PORT 8848 /* multicast port */
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2010-11-19 06:25:11 -07:00
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#define SYNC_PROTO_VER 1 /* Protocol version in header */
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2005-04-16 16:20:36 -06:00
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2011-10-10 19:54:35 -06:00
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static struct lock_class_key __ipvs_sync_key;
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2005-04-16 16:20:36 -06:00
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/*
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* IPVS sync connection entry
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2010-11-19 06:25:11 -07:00
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* Version 0, i.e. original version.
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2005-04-16 16:20:36 -06:00
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*/
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2010-11-19 06:25:11 -07:00
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|
|
struct ip_vs_sync_conn_v0 {
|
2005-04-16 16:20:36 -06:00
|
|
|
__u8 reserved;
|
|
|
|
|
|
|
|
/* Protocol, addresses and port numbers */
|
|
|
|
__u8 protocol; /* Which protocol (TCP/UDP) */
|
2006-09-28 15:29:52 -06:00
|
|
|
__be16 cport;
|
|
|
|
__be16 vport;
|
|
|
|
__be16 dport;
|
|
|
|
__be32 caddr; /* client address */
|
|
|
|
__be32 vaddr; /* virtual address */
|
|
|
|
__be32 daddr; /* destination address */
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* Flags and state transition */
|
2006-09-28 15:29:52 -06:00
|
|
|
__be16 flags; /* status flags */
|
|
|
|
__be16 state; /* state info */
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* The sequence options start here */
|
|
|
|
};
|
|
|
|
|
|
|
|
struct ip_vs_sync_conn_options {
|
|
|
|
struct ip_vs_seq in_seq; /* incoming seq. struct */
|
|
|
|
struct ip_vs_seq out_seq; /* outgoing seq. struct */
|
|
|
|
};
|
|
|
|
|
2010-11-19 06:25:11 -07:00
|
|
|
/*
|
|
|
|
Sync Connection format (sync_conn)
|
|
|
|
|
|
|
|
0 1 2 3
|
|
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| Type | Protocol | Ver. | Size |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| Flags |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| State | cport |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| vport | dport |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| fwmark |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| timeout (in sec.) |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| ... |
|
|
|
|
| IP-Addresses (v4 or v6) |
|
|
|
|
| ... |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
Optional Parameters.
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| Param. Type | Param. Length | Param. data |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
|
|
|
|
| ... |
|
|
|
|
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| | Param Type | Param. Length |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| Param data |
|
|
|
|
| Last Param data should be padded for 32 bit alignment |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Type 0, IPv4 sync connection format
|
|
|
|
*/
|
|
|
|
struct ip_vs_sync_v4 {
|
|
|
|
__u8 type;
|
|
|
|
__u8 protocol; /* Which protocol (TCP/UDP) */
|
|
|
|
__be16 ver_size; /* Version msb 4 bits */
|
|
|
|
/* Flags and state transition */
|
|
|
|
__be32 flags; /* status flags */
|
|
|
|
__be16 state; /* state info */
|
|
|
|
/* Protocol, addresses and port numbers */
|
|
|
|
__be16 cport;
|
|
|
|
__be16 vport;
|
|
|
|
__be16 dport;
|
|
|
|
__be32 fwmark; /* Firewall mark from skb */
|
|
|
|
__be32 timeout; /* cp timeout */
|
|
|
|
__be32 caddr; /* client address */
|
|
|
|
__be32 vaddr; /* virtual address */
|
|
|
|
__be32 daddr; /* destination address */
|
|
|
|
/* The sequence options start here */
|
|
|
|
/* PE data padded to 32bit alignment after seq. options */
|
|
|
|
};
|
|
|
|
/*
|
|
|
|
* Type 2 messages IPv6
|
|
|
|
*/
|
|
|
|
struct ip_vs_sync_v6 {
|
|
|
|
__u8 type;
|
|
|
|
__u8 protocol; /* Which protocol (TCP/UDP) */
|
|
|
|
__be16 ver_size; /* Version msb 4 bits */
|
|
|
|
/* Flags and state transition */
|
|
|
|
__be32 flags; /* status flags */
|
|
|
|
__be16 state; /* state info */
|
|
|
|
/* Protocol, addresses and port numbers */
|
|
|
|
__be16 cport;
|
|
|
|
__be16 vport;
|
|
|
|
__be16 dport;
|
|
|
|
__be32 fwmark; /* Firewall mark from skb */
|
|
|
|
__be32 timeout; /* cp timeout */
|
|
|
|
struct in6_addr caddr; /* client address */
|
|
|
|
struct in6_addr vaddr; /* virtual address */
|
|
|
|
struct in6_addr daddr; /* destination address */
|
|
|
|
/* The sequence options start here */
|
|
|
|
/* PE data padded to 32bit alignment after seq. options */
|
|
|
|
};
|
|
|
|
|
|
|
|
union ip_vs_sync_conn {
|
|
|
|
struct ip_vs_sync_v4 v4;
|
|
|
|
struct ip_vs_sync_v6 v6;
|
|
|
|
};
|
|
|
|
|
|
|
|
/* Bits in Type field in above */
|
|
|
|
#define STYPE_INET6 0
|
|
|
|
#define STYPE_F_INET6 (1 << STYPE_INET6)
|
|
|
|
|
|
|
|
#define SVER_SHIFT 12 /* Shift to get version */
|
|
|
|
#define SVER_MASK 0x0fff /* Mask to strip version */
|
|
|
|
|
|
|
|
#define IPVS_OPT_SEQ_DATA 1
|
|
|
|
#define IPVS_OPT_PE_DATA 2
|
|
|
|
#define IPVS_OPT_PE_NAME 3
|
|
|
|
#define IPVS_OPT_PARAM 7
|
|
|
|
|
|
|
|
#define IPVS_OPT_F_SEQ_DATA (1 << (IPVS_OPT_SEQ_DATA-1))
|
|
|
|
#define IPVS_OPT_F_PE_DATA (1 << (IPVS_OPT_PE_DATA-1))
|
|
|
|
#define IPVS_OPT_F_PE_NAME (1 << (IPVS_OPT_PE_NAME-1))
|
|
|
|
#define IPVS_OPT_F_PARAM (1 << (IPVS_OPT_PARAM-1))
|
|
|
|
|
2007-06-18 23:33:20 -06:00
|
|
|
struct ip_vs_sync_thread_data {
|
2015-09-21 12:02:14 -06:00
|
|
|
struct netns_ipvs *ipvs;
|
2008-07-16 05:13:50 -06:00
|
|
|
struct socket *sock;
|
|
|
|
char *buf;
|
2012-05-08 11:40:30 -06:00
|
|
|
int id;
|
2007-06-18 23:33:20 -06:00
|
|
|
};
|
|
|
|
|
2010-11-19 06:25:11 -07:00
|
|
|
/* Version 0 definition of packet sizes */
|
|
|
|
#define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn_v0))
|
2005-04-16 16:20:36 -06:00
|
|
|
#define FULL_CONN_SIZE \
|
2010-11-19 06:25:11 -07:00
|
|
|
(sizeof(struct ip_vs_sync_conn_v0) + sizeof(struct ip_vs_sync_conn_options))
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
|
|
|
|
/*
|
2010-11-19 06:25:11 -07:00
|
|
|
The master mulitcasts messages (Datagrams) to the backup load balancers
|
|
|
|
in the following format.
|
|
|
|
|
|
|
|
Version 1:
|
|
|
|
Note, first byte should be Zero, so ver 0 receivers will drop the packet.
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
0 1 2 3
|
|
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
2010-11-19 06:25:11 -07:00
|
|
|
| 0 | SyncID | Size |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| Count Conns | Version | Reserved, set to Zero |
|
2005-04-16 16:20:36 -06:00
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| |
|
|
|
|
| IPVS Sync Connection (1) |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| . |
|
2010-11-19 06:25:11 -07:00
|
|
|
~ . ~
|
2005-04-16 16:20:36 -06:00
|
|
|
| . |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| |
|
|
|
|
| IPVS Sync Connection (n) |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
2010-11-19 06:25:11 -07:00
|
|
|
|
|
|
|
Version 0 Header
|
|
|
|
0 1 2 3
|
|
|
|
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| Count Conns | SyncID | Size |
|
|
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
|
|
| IPVS Sync Connection (1) |
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
|
|
|
|
|
|
|
#define SYNC_MESG_HEADER_LEN 4
|
2008-09-19 12:41:56 -06:00
|
|
|
#define MAX_CONNS_PER_SYNCBUFF 255 /* nr_conns in ip_vs_sync_mesg is 8 bit */
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-11-19 06:25:11 -07:00
|
|
|
/* Version 0 header */
|
2010-11-19 06:25:13 -07:00
|
|
|
struct ip_vs_sync_mesg_v0 {
|
2005-04-16 16:20:36 -06:00
|
|
|
__u8 nr_conns;
|
|
|
|
__u8 syncid;
|
2013-04-18 19:43:44 -06:00
|
|
|
__be16 size;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* ip_vs_sync_conn entries start here */
|
|
|
|
};
|
|
|
|
|
2010-11-19 06:25:11 -07:00
|
|
|
/* Version 1 header */
|
2010-11-19 06:25:13 -07:00
|
|
|
struct ip_vs_sync_mesg {
|
2010-11-19 06:25:11 -07:00
|
|
|
__u8 reserved; /* must be zero */
|
|
|
|
__u8 syncid;
|
2013-04-18 19:43:44 -06:00
|
|
|
__be16 size;
|
2010-11-19 06:25:11 -07:00
|
|
|
__u8 nr_conns;
|
|
|
|
__s8 version; /* SYNC_PROTO_VER */
|
|
|
|
__u16 spare;
|
|
|
|
/* ip_vs_sync_conn entries start here */
|
|
|
|
};
|
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
union ipvs_sockaddr {
|
|
|
|
struct sockaddr_in in;
|
|
|
|
struct sockaddr_in6 in6;
|
|
|
|
};
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
struct ip_vs_sync_buff {
|
|
|
|
struct list_head list;
|
|
|
|
unsigned long firstuse;
|
|
|
|
|
|
|
|
/* pointers for the message data */
|
|
|
|
struct ip_vs_sync_mesg *mesg;
|
|
|
|
unsigned char *head;
|
|
|
|
unsigned char *end;
|
|
|
|
};
|
|
|
|
|
2010-11-19 06:25:12 -07:00
|
|
|
/*
|
|
|
|
* Copy of struct ip_vs_seq
|
|
|
|
* From unaligned network order to aligned host order
|
|
|
|
*/
|
|
|
|
static void ntoh_seq(struct ip_vs_seq *no, struct ip_vs_seq *ho)
|
|
|
|
{
|
netfilter: ip_vs_sync: fix bogus maybe-uninitialized warning
Building the ip_vs_sync code with CONFIG_OPTIMIZE_INLINING on x86
confuses the compiler to the point where it produces a rather
dubious warning message:
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘opt.init_seq’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
struct ip_vs_sync_conn_options opt;
^~~
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘opt.delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘opt.previous_delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘*((void *)&opt+12).init_seq’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘*((void *)&opt+12).delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘*((void *)&opt+12).previous_delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
The problem appears to be a combination of a number of factors, including
the __builtin_bswap32 compiler builtin being slightly odd, having a large
amount of code inlined into a single function, and the way that some
functions only get partially inlined here.
I've spent way too much time trying to work out a way to improve the
code, but the best I've come up with is to add an explicit memset
right before the ip_vs_seq structure is first initialized here. When
the compiler works correctly, this has absolutely no effect, but in the
case that produces the warning, the warning disappears.
In the process of analysing this warning, I also noticed that
we use memcpy to copy the larger ip_vs_sync_conn_options structure
over two members of the ip_vs_conn structure. This works because
the layout is identical, but seems error-prone, so I'm changing
this in the process to directly copy the two members. This change
seemed to have no effect on the object code or the warning, but
it deals with the same data, so I kept the two changes together.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-24 09:34:32 -06:00
|
|
|
memset(ho, 0, sizeof(*ho));
|
2010-11-19 06:25:12 -07:00
|
|
|
ho->init_seq = get_unaligned_be32(&no->init_seq);
|
|
|
|
ho->delta = get_unaligned_be32(&no->delta);
|
|
|
|
ho->previous_delta = get_unaligned_be32(&no->previous_delta);
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
/*
|
|
|
|
* Copy of struct ip_vs_seq
|
|
|
|
* From Aligned host order to unaligned network order
|
|
|
|
*/
|
|
|
|
static void hton_seq(struct ip_vs_seq *ho, struct ip_vs_seq *no)
|
|
|
|
{
|
|
|
|
put_unaligned_be32(ho->init_seq, &no->init_seq);
|
|
|
|
put_unaligned_be32(ho->delta, &no->delta);
|
|
|
|
put_unaligned_be32(ho->previous_delta, &no->previous_delta);
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
static inline struct ip_vs_sync_buff *
|
|
|
|
sb_dequeue(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_buff *sb;
|
|
|
|
|
2011-01-03 06:44:55 -07:00
|
|
|
spin_lock_bh(&ipvs->sync_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (list_empty(&ms->sync_queue)) {
|
2005-04-16 16:20:36 -06:00
|
|
|
sb = NULL;
|
2012-05-08 11:39:49 -06:00
|
|
|
__set_current_state(TASK_INTERRUPTIBLE);
|
2005-04-16 16:20:36 -06:00
|
|
|
} else {
|
2012-05-08 11:40:30 -06:00
|
|
|
sb = list_entry(ms->sync_queue.next, struct ip_vs_sync_buff,
|
2005-04-16 16:20:36 -06:00
|
|
|
list);
|
|
|
|
list_del(&sb->list);
|
2012-05-08 11:40:30 -06:00
|
|
|
ms->sync_queue_len--;
|
|
|
|
if (!ms->sync_queue_len)
|
|
|
|
ms->sync_queue_delay = 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2011-01-03 06:44:55 -07:00
|
|
|
spin_unlock_bh(&ipvs->sync_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
return sb;
|
|
|
|
}
|
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
/*
|
|
|
|
* Create a new sync buffer for Version 1 proto.
|
|
|
|
*/
|
2011-01-03 06:44:55 -07:00
|
|
|
static inline struct ip_vs_sync_buff *
|
2015-07-26 06:03:27 -06:00
|
|
|
ip_vs_sync_buff_create(struct netns_ipvs *ipvs, unsigned int len)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_buff *sb;
|
|
|
|
|
|
|
|
if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
|
|
|
|
return NULL;
|
|
|
|
|
2015-07-26 06:03:27 -06:00
|
|
|
len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg),
|
|
|
|
ipvs->mcfg.sync_maxlen);
|
|
|
|
sb->mesg = kmalloc(len, GFP_ATOMIC);
|
2011-01-03 06:44:55 -07:00
|
|
|
if (!sb->mesg) {
|
2005-04-16 16:20:36 -06:00
|
|
|
kfree(sb);
|
|
|
|
return NULL;
|
|
|
|
}
|
2012-05-08 11:40:30 -06:00
|
|
|
sb->mesg->reserved = 0; /* old nr_conns i.e. must be zero now */
|
2010-11-19 06:25:13 -07:00
|
|
|
sb->mesg->version = SYNC_PROTO_VER;
|
2015-07-26 06:03:27 -06:00
|
|
|
sb->mesg->syncid = ipvs->mcfg.syncid;
|
2013-04-18 19:43:44 -06:00
|
|
|
sb->mesg->size = htons(sizeof(struct ip_vs_sync_mesg));
|
2010-11-19 06:25:13 -07:00
|
|
|
sb->mesg->nr_conns = 0;
|
|
|
|
sb->mesg->spare = 0;
|
|
|
|
sb->head = (unsigned char *)sb->mesg + sizeof(struct ip_vs_sync_mesg);
|
2015-07-26 06:03:27 -06:00
|
|
|
sb->end = (unsigned char *)sb->mesg + len;
|
2010-11-19 06:25:13 -07:00
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
sb->firstuse = jiffies;
|
|
|
|
return sb;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
|
|
|
|
{
|
|
|
|
kfree(sb->mesg);
|
|
|
|
kfree(sb);
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
static inline void sb_queue_tail(struct netns_ipvs *ipvs,
|
|
|
|
struct ipvs_master_sync_state *ms)
|
2008-07-16 05:13:50 -06:00
|
|
|
{
|
2012-05-08 11:40:30 -06:00
|
|
|
struct ip_vs_sync_buff *sb = ms->sync_buff;
|
2011-01-03 06:44:55 -07:00
|
|
|
|
|
|
|
spin_lock(&ipvs->sync_lock);
|
2012-05-08 11:39:49 -06:00
|
|
|
if (ipvs->sync_state & IP_VS_STATE_MASTER &&
|
2012-05-08 11:40:30 -06:00
|
|
|
ms->sync_queue_len < sysctl_sync_qlen_max(ipvs)) {
|
|
|
|
if (!ms->sync_queue_len)
|
|
|
|
schedule_delayed_work(&ms->master_wakeup_work,
|
2012-05-08 11:39:49 -06:00
|
|
|
max(IPVS_SYNC_SEND_DELAY, 1));
|
2012-05-08 11:40:30 -06:00
|
|
|
ms->sync_queue_len++;
|
|
|
|
list_add_tail(&sb->list, &ms->sync_queue);
|
|
|
|
if ((++ms->sync_queue_delay) == IPVS_SYNC_WAKEUP_RATE)
|
|
|
|
wake_up_process(ms->master_thread);
|
2012-05-08 11:39:49 -06:00
|
|
|
} else
|
2008-07-16 05:13:50 -06:00
|
|
|
ip_vs_sync_buff_release(sb);
|
2011-01-03 06:44:55 -07:00
|
|
|
spin_unlock(&ipvs->sync_lock);
|
2008-07-16 05:13:50 -06:00
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* Get the current sync buffer if it has been created for more
|
|
|
|
* than the specified time or the specified time is zero.
|
|
|
|
*/
|
|
|
|
static inline struct ip_vs_sync_buff *
|
2012-05-08 11:40:30 -06:00
|
|
|
get_curr_sync_buff(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms,
|
|
|
|
unsigned long time)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_buff *sb;
|
|
|
|
|
2011-01-03 06:44:55 -07:00
|
|
|
spin_lock_bh(&ipvs->sync_buff_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
sb = ms->sync_buff;
|
|
|
|
if (sb && time_after_eq(jiffies - sb->firstuse, time)) {
|
|
|
|
ms->sync_buff = NULL;
|
2012-05-08 11:39:49 -06:00
|
|
|
__set_current_state(TASK_RUNNING);
|
2005-04-16 16:20:36 -06:00
|
|
|
} else
|
|
|
|
sb = NULL;
|
2011-01-03 06:44:55 -07:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
return sb;
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
static inline int
|
|
|
|
select_master_thread_id(struct netns_ipvs *ipvs, struct ip_vs_conn *cp)
|
2011-01-03 06:44:55 -07:00
|
|
|
{
|
2012-05-08 11:40:30 -06:00
|
|
|
return ((long) cp >> (1 + ilog2(sizeof(*cp)))) & ipvs->threads_mask;
|
2010-11-19 06:25:14 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Create a new sync buffer for Version 0 proto.
|
|
|
|
*/
|
2011-01-03 06:44:55 -07:00
|
|
|
static inline struct ip_vs_sync_buff *
|
2015-07-26 06:03:27 -06:00
|
|
|
ip_vs_sync_buff_create_v0(struct netns_ipvs *ipvs, unsigned int len)
|
2010-11-19 06:25:14 -07:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_buff *sb;
|
|
|
|
struct ip_vs_sync_mesg_v0 *mesg;
|
|
|
|
|
|
|
|
if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
|
|
|
|
return NULL;
|
|
|
|
|
2015-07-26 06:03:27 -06:00
|
|
|
len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg_v0),
|
|
|
|
ipvs->mcfg.sync_maxlen);
|
|
|
|
sb->mesg = kmalloc(len, GFP_ATOMIC);
|
2011-01-03 06:44:55 -07:00
|
|
|
if (!sb->mesg) {
|
2010-11-19 06:25:14 -07:00
|
|
|
kfree(sb);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
mesg = (struct ip_vs_sync_mesg_v0 *)sb->mesg;
|
|
|
|
mesg->nr_conns = 0;
|
2015-07-26 06:03:27 -06:00
|
|
|
mesg->syncid = ipvs->mcfg.syncid;
|
2013-04-18 19:43:44 -06:00
|
|
|
mesg->size = htons(sizeof(struct ip_vs_sync_mesg_v0));
|
2011-01-03 06:44:55 -07:00
|
|
|
sb->head = (unsigned char *)mesg + sizeof(struct ip_vs_sync_mesg_v0);
|
2015-07-26 06:03:27 -06:00
|
|
|
sb->end = (unsigned char *)mesg + len;
|
2010-11-19 06:25:14 -07:00
|
|
|
sb->firstuse = jiffies;
|
|
|
|
return sb;
|
|
|
|
}
|
|
|
|
|
2013-06-24 13:44:41 -06:00
|
|
|
/* Check if connection is controlled by persistence */
|
|
|
|
static inline bool in_persistence(struct ip_vs_conn *cp)
|
|
|
|
{
|
|
|
|
for (cp = cp->control; cp; cp = cp->control) {
|
|
|
|
if (cp->flags & IP_VS_CONN_F_TEMPLATE)
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
2012-04-24 14:46:40 -06:00
|
|
|
/* Check if conn should be synced.
|
|
|
|
* pkts: conn packets, use sysctl_sync_threshold to avoid packet check
|
|
|
|
* - (1) sync_refresh_period: reduce sync rate. Additionally, retry
|
|
|
|
* sync_retries times with period of sync_refresh_period/8
|
|
|
|
* - (2) if both sync_refresh_period and sync_period are 0 send sync only
|
|
|
|
* for state changes or only once when pkts matches sync_threshold
|
|
|
|
* - (3) templates: rate can be reduced only with sync_refresh_period or
|
|
|
|
* with (2)
|
|
|
|
*/
|
|
|
|
static int ip_vs_sync_conn_needed(struct netns_ipvs *ipvs,
|
|
|
|
struct ip_vs_conn *cp, int pkts)
|
|
|
|
{
|
locking/atomics, net/netlink/netfilter: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE()
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't currently harmful.
However, for some features it is necessary to instrument reads and
writes separately, which is not possible with ACCESS_ONCE(). This
distinction is critical to correct operation.
It's possible to transform the bulk of kernel code using the Coccinelle
script below. However, this doesn't handle comments, leaving references
to ACCESS_ONCE() instances which have been removed. As a preparatory
step, this patch converts netlink and netfilter code and comments to use
{READ,WRITE}_ONCE() consistently.
----
virtual patch
@ depends on patch @
expression E1, E2;
@@
- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)
@ depends on patch @
expression E;
@@
- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Florian Westphal <fw@strlen.de>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-7-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 15:07:17 -06:00
|
|
|
unsigned long orig = READ_ONCE(cp->sync_endtime);
|
2012-04-24 14:46:40 -06:00
|
|
|
unsigned long now = jiffies;
|
|
|
|
unsigned long n = (now + cp->timeout) & ~3UL;
|
|
|
|
unsigned int sync_refresh_period;
|
|
|
|
int sync_period;
|
|
|
|
int force;
|
|
|
|
|
|
|
|
/* Check if we sync in current state */
|
|
|
|
if (unlikely(cp->flags & IP_VS_CONN_F_TEMPLATE))
|
|
|
|
force = 0;
|
2013-06-24 13:44:41 -06:00
|
|
|
else if (unlikely(sysctl_sync_persist_mode(ipvs) && in_persistence(cp)))
|
|
|
|
return 0;
|
2012-04-24 14:46:40 -06:00
|
|
|
else if (likely(cp->protocol == IPPROTO_TCP)) {
|
|
|
|
if (!((1 << cp->state) &
|
|
|
|
((1 << IP_VS_TCP_S_ESTABLISHED) |
|
|
|
|
(1 << IP_VS_TCP_S_FIN_WAIT) |
|
|
|
|
(1 << IP_VS_TCP_S_CLOSE) |
|
|
|
|
(1 << IP_VS_TCP_S_CLOSE_WAIT) |
|
|
|
|
(1 << IP_VS_TCP_S_TIME_WAIT))))
|
|
|
|
return 0;
|
|
|
|
force = cp->state != cp->old_state;
|
|
|
|
if (force && cp->state != IP_VS_TCP_S_ESTABLISHED)
|
|
|
|
goto set;
|
|
|
|
} else if (unlikely(cp->protocol == IPPROTO_SCTP)) {
|
|
|
|
if (!((1 << cp->state) &
|
|
|
|
((1 << IP_VS_SCTP_S_ESTABLISHED) |
|
2013-06-18 01:08:07 -06:00
|
|
|
(1 << IP_VS_SCTP_S_SHUTDOWN_SENT) |
|
|
|
|
(1 << IP_VS_SCTP_S_SHUTDOWN_RECEIVED) |
|
|
|
|
(1 << IP_VS_SCTP_S_SHUTDOWN_ACK_SENT) |
|
|
|
|
(1 << IP_VS_SCTP_S_CLOSED))))
|
2012-04-24 14:46:40 -06:00
|
|
|
return 0;
|
|
|
|
force = cp->state != cp->old_state;
|
|
|
|
if (force && cp->state != IP_VS_SCTP_S_ESTABLISHED)
|
|
|
|
goto set;
|
|
|
|
} else {
|
|
|
|
/* UDP or another protocol with single state */
|
|
|
|
force = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
sync_refresh_period = sysctl_sync_refresh_period(ipvs);
|
|
|
|
if (sync_refresh_period > 0) {
|
|
|
|
long diff = n - orig;
|
|
|
|
long min_diff = max(cp->timeout >> 1, 10UL * HZ);
|
|
|
|
|
|
|
|
/* Avoid sync if difference is below sync_refresh_period
|
|
|
|
* and below the half timeout.
|
|
|
|
*/
|
|
|
|
if (abs(diff) < min_t(long, sync_refresh_period, min_diff)) {
|
|
|
|
int retries = orig & 3;
|
|
|
|
|
|
|
|
if (retries >= sysctl_sync_retries(ipvs))
|
|
|
|
return 0;
|
|
|
|
if (time_before(now, orig - cp->timeout +
|
|
|
|
(sync_refresh_period >> 3)))
|
|
|
|
return 0;
|
|
|
|
n |= retries + 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
sync_period = sysctl_sync_period(ipvs);
|
|
|
|
if (sync_period > 0) {
|
|
|
|
if (!(cp->flags & IP_VS_CONN_F_TEMPLATE) &&
|
|
|
|
pkts % sync_period != sysctl_sync_threshold(ipvs))
|
|
|
|
return 0;
|
2017-04-12 14:38:12 -06:00
|
|
|
} else if (!sync_refresh_period &&
|
2012-04-24 14:46:40 -06:00
|
|
|
pkts != sysctl_sync_threshold(ipvs))
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
set:
|
|
|
|
cp->old_state = cp->state;
|
|
|
|
n = cmpxchg(&cp->sync_endtime, orig, n);
|
|
|
|
return n == orig || force;
|
|
|
|
}
|
|
|
|
|
2010-11-19 06:25:14 -07:00
|
|
|
/*
|
|
|
|
* Version 0 , could be switched in by sys_ctl.
|
|
|
|
* Add an ip_vs_conn information into the current sync_buff.
|
|
|
|
*/
|
2015-09-21 12:02:16 -06:00
|
|
|
static void ip_vs_sync_conn_v0(struct netns_ipvs *ipvs, struct ip_vs_conn *cp,
|
2012-04-24 14:46:40 -06:00
|
|
|
int pkts)
|
2010-11-19 06:25:14 -07:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_mesg_v0 *m;
|
|
|
|
struct ip_vs_sync_conn_v0 *s;
|
2012-05-08 11:40:30 -06:00
|
|
|
struct ip_vs_sync_buff *buff;
|
|
|
|
struct ipvs_master_sync_state *ms;
|
|
|
|
int id;
|
2015-07-26 06:03:27 -06:00
|
|
|
unsigned int len;
|
2010-11-19 06:25:14 -07:00
|
|
|
|
|
|
|
if (unlikely(cp->af != AF_INET))
|
|
|
|
return;
|
|
|
|
/* Do not sync ONE PACKET */
|
|
|
|
if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
|
|
|
|
return;
|
|
|
|
|
2012-04-24 14:46:40 -06:00
|
|
|
if (!ip_vs_sync_conn_needed(ipvs, cp, pkts))
|
|
|
|
return;
|
|
|
|
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_lock_bh(&ipvs->sync_buff_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
id = select_master_thread_id(ipvs, cp);
|
|
|
|
ms = &ipvs->ms[id];
|
|
|
|
buff = ms->sync_buff;
|
2015-07-26 06:03:27 -06:00
|
|
|
len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
|
|
|
|
SIMPLE_CONN_SIZE;
|
2012-05-08 11:40:30 -06:00
|
|
|
if (buff) {
|
|
|
|
m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
|
|
|
|
/* Send buffer if it is for v1 */
|
2015-07-26 06:03:27 -06:00
|
|
|
if (buff->head + len > buff->end || !m->nr_conns) {
|
2012-05-08 11:40:30 -06:00
|
|
|
sb_queue_tail(ipvs, ms);
|
|
|
|
ms->sync_buff = NULL;
|
|
|
|
buff = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (!buff) {
|
2015-07-26 06:03:27 -06:00
|
|
|
buff = ip_vs_sync_buff_create_v0(ipvs, len);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!buff) {
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2010-11-19 06:25:14 -07:00
|
|
|
pr_err("ip_vs_sync_buff_create failed.\n");
|
|
|
|
return;
|
|
|
|
}
|
2012-05-08 11:40:30 -06:00
|
|
|
ms->sync_buff = buff;
|
2010-11-19 06:25:14 -07:00
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
|
|
|
|
s = (struct ip_vs_sync_conn_v0 *) buff->head;
|
2010-11-19 06:25:14 -07:00
|
|
|
|
|
|
|
/* copy members */
|
|
|
|
s->reserved = 0;
|
|
|
|
s->protocol = cp->protocol;
|
|
|
|
s->cport = cp->cport;
|
|
|
|
s->vport = cp->vport;
|
|
|
|
s->dport = cp->dport;
|
|
|
|
s->caddr = cp->caddr.ip;
|
|
|
|
s->vaddr = cp->vaddr.ip;
|
|
|
|
s->daddr = cp->daddr.ip;
|
|
|
|
s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
|
|
|
|
s->state = htons(cp->state);
|
|
|
|
if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
|
|
|
|
struct ip_vs_sync_conn_options *opt =
|
|
|
|
(struct ip_vs_sync_conn_options *)&s[1];
|
|
|
|
memcpy(opt, &cp->in_seq, sizeof(*opt));
|
|
|
|
}
|
|
|
|
|
|
|
|
m->nr_conns++;
|
2013-04-18 19:43:44 -06:00
|
|
|
m->size = htons(ntohs(m->size) + len);
|
2012-05-08 11:40:30 -06:00
|
|
|
buff->head += len;
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2010-11-19 06:25:14 -07:00
|
|
|
|
|
|
|
/* synchronize its controller if it has */
|
2012-04-24 14:46:40 -06:00
|
|
|
cp = cp->control;
|
|
|
|
if (cp) {
|
|
|
|
if (cp->flags & IP_VS_CONN_F_TEMPLATE)
|
|
|
|
pkts = atomic_add_return(1, &cp->in_pkts);
|
|
|
|
else
|
|
|
|
pkts = sysctl_sync_threshold(ipvs);
|
2015-09-21 12:02:17 -06:00
|
|
|
ip_vs_sync_conn(ipvs, cp, pkts);
|
2012-04-24 14:46:40 -06:00
|
|
|
}
|
2010-11-19 06:25:14 -07:00
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* Add an ip_vs_conn information into the current sync_buff.
|
|
|
|
* Called by ip_vs_in.
|
2010-11-19 06:25:13 -07:00
|
|
|
* Sending Version 1 messages
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
2015-09-21 12:02:17 -06:00
|
|
|
void ip_vs_sync_conn(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_mesg *m;
|
2010-11-19 06:25:13 -07:00
|
|
|
union ip_vs_sync_conn *s;
|
2012-05-08 11:40:30 -06:00
|
|
|
struct ip_vs_sync_buff *buff;
|
|
|
|
struct ipvs_master_sync_state *ms;
|
|
|
|
int id;
|
2010-11-19 06:25:13 -07:00
|
|
|
__u8 *p;
|
|
|
|
unsigned int len, pe_name_len, pad;
|
|
|
|
|
2010-11-19 06:25:14 -07:00
|
|
|
/* Handle old version of the protocol */
|
2011-02-04 02:33:01 -07:00
|
|
|
if (sysctl_sync_ver(ipvs) == 0) {
|
2015-09-21 12:02:16 -06:00
|
|
|
ip_vs_sync_conn_v0(ipvs, cp, pkts);
|
2010-11-19 06:25:14 -07:00
|
|
|
return;
|
|
|
|
}
|
2010-11-19 06:25:13 -07:00
|
|
|
/* Do not sync ONE PACKET */
|
|
|
|
if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
|
|
|
|
goto control;
|
|
|
|
sloop:
|
2012-04-24 14:46:40 -06:00
|
|
|
if (!ip_vs_sync_conn_needed(ipvs, cp, pkts))
|
|
|
|
goto control;
|
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
/* Sanity checks */
|
|
|
|
pe_name_len = 0;
|
|
|
|
if (cp->pe_data_len) {
|
|
|
|
if (!cp->pe_data || !cp->dest) {
|
|
|
|
IP_VS_ERR_RL("SYNC, connection pe_data invalid\n");
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
pe_name_len = strnlen(cp->pe->name, IP_VS_PENAME_MAXLEN);
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_lock_bh(&ipvs->sync_buff_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
id = select_master_thread_id(ipvs, cp);
|
|
|
|
ms = &ipvs->ms[id];
|
2010-11-19 06:25:13 -07:00
|
|
|
|
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (cp->af == AF_INET6)
|
|
|
|
len = sizeof(struct ip_vs_sync_v6);
|
|
|
|
else
|
|
|
|
#endif
|
|
|
|
len = sizeof(struct ip_vs_sync_v4);
|
|
|
|
|
|
|
|
if (cp->flags & IP_VS_CONN_F_SEQ_MASK)
|
|
|
|
len += sizeof(struct ip_vs_sync_conn_options) + 2;
|
|
|
|
|
|
|
|
if (cp->pe_data_len)
|
|
|
|
len += cp->pe_data_len + 2; /* + Param hdr field */
|
|
|
|
if (pe_name_len)
|
|
|
|
len += pe_name_len + 2;
|
|
|
|
|
|
|
|
/* check if there is a space for this one */
|
|
|
|
pad = 0;
|
2012-05-08 11:40:30 -06:00
|
|
|
buff = ms->sync_buff;
|
|
|
|
if (buff) {
|
|
|
|
m = buff->mesg;
|
|
|
|
pad = (4 - (size_t) buff->head) & 3;
|
|
|
|
/* Send buffer if it is for v0 */
|
|
|
|
if (buff->head + len + pad > buff->end || m->reserved) {
|
|
|
|
sb_queue_tail(ipvs, ms);
|
|
|
|
ms->sync_buff = NULL;
|
|
|
|
buff = NULL;
|
2010-11-19 06:25:13 -07:00
|
|
|
pad = 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!buff) {
|
2015-07-26 06:03:27 -06:00
|
|
|
buff = ip_vs_sync_buff_create(ipvs, len);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!buff) {
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("ip_vs_sync_buff_create failed.\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
return;
|
|
|
|
}
|
2012-05-08 11:40:30 -06:00
|
|
|
ms->sync_buff = buff;
|
|
|
|
m = buff->mesg;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
p = buff->head;
|
|
|
|
buff->head += pad + len;
|
2013-04-18 19:43:44 -06:00
|
|
|
m->size = htons(ntohs(m->size) + pad + len);
|
2010-11-19 06:25:13 -07:00
|
|
|
/* Add ev. padding from prev. sync_conn */
|
|
|
|
while (pad--)
|
|
|
|
*(p++) = 0;
|
|
|
|
|
|
|
|
s = (union ip_vs_sync_conn *)p;
|
|
|
|
|
|
|
|
/* Set message type & copy members */
|
|
|
|
s->v4.type = (cp->af == AF_INET6 ? STYPE_F_INET6 : 0);
|
|
|
|
s->v4.ver_size = htons(len & SVER_MASK); /* Version 0 */
|
|
|
|
s->v4.flags = htonl(cp->flags & ~IP_VS_CONN_F_HASHED);
|
|
|
|
s->v4.state = htons(cp->state);
|
|
|
|
s->v4.protocol = cp->protocol;
|
|
|
|
s->v4.cport = cp->cport;
|
|
|
|
s->v4.vport = cp->vport;
|
|
|
|
s->v4.dport = cp->dport;
|
|
|
|
s->v4.fwmark = htonl(cp->fwmark);
|
|
|
|
s->v4.timeout = htonl(cp->timeout / HZ);
|
2005-04-16 16:20:36 -06:00
|
|
|
m->nr_conns++;
|
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (cp->af == AF_INET6) {
|
|
|
|
p += sizeof(struct ip_vs_sync_v6);
|
2011-11-20 20:39:03 -07:00
|
|
|
s->v6.caddr = cp->caddr.in6;
|
|
|
|
s->v6.vaddr = cp->vaddr.in6;
|
|
|
|
s->v6.daddr = cp->daddr.in6;
|
2010-11-19 06:25:13 -07:00
|
|
|
} else
|
|
|
|
#endif
|
|
|
|
{
|
|
|
|
p += sizeof(struct ip_vs_sync_v4); /* options ptr */
|
|
|
|
s->v4.caddr = cp->caddr.ip;
|
|
|
|
s->v4.vaddr = cp->vaddr.ip;
|
|
|
|
s->v4.daddr = cp->daddr.ip;
|
|
|
|
}
|
|
|
|
if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
|
|
|
|
*(p++) = IPVS_OPT_SEQ_DATA;
|
|
|
|
*(p++) = sizeof(struct ip_vs_sync_conn_options);
|
|
|
|
hton_seq((struct ip_vs_seq *)p, &cp->in_seq);
|
|
|
|
p += sizeof(struct ip_vs_seq);
|
|
|
|
hton_seq((struct ip_vs_seq *)p, &cp->out_seq);
|
|
|
|
p += sizeof(struct ip_vs_seq);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2010-11-19 06:25:13 -07:00
|
|
|
/* Handle pe data */
|
|
|
|
if (cp->pe_data_len && cp->pe_data) {
|
|
|
|
*(p++) = IPVS_OPT_PE_DATA;
|
|
|
|
*(p++) = cp->pe_data_len;
|
|
|
|
memcpy(p, cp->pe_data, cp->pe_data_len);
|
|
|
|
p += cp->pe_data_len;
|
|
|
|
if (pe_name_len) {
|
|
|
|
/* Add PE_NAME */
|
|
|
|
*(p++) = IPVS_OPT_PE_NAME;
|
|
|
|
*(p++) = pe_name_len;
|
|
|
|
memcpy(p, cp->pe->name, pe_name_len);
|
|
|
|
p += pe_name_len;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
control:
|
2005-04-16 16:20:36 -06:00
|
|
|
/* synchronize its controller if it has */
|
2010-11-19 06:25:13 -07:00
|
|
|
cp = cp->control;
|
|
|
|
if (!cp)
|
|
|
|
return;
|
2012-04-24 14:46:40 -06:00
|
|
|
if (cp->flags & IP_VS_CONN_F_TEMPLATE)
|
|
|
|
pkts = atomic_add_return(1, &cp->in_pkts);
|
|
|
|
else
|
|
|
|
pkts = sysctl_sync_threshold(ipvs);
|
2010-11-19 06:25:13 -07:00
|
|
|
goto sloop;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2010-11-19 06:25:12 -07:00
|
|
|
/*
|
|
|
|
* fill_param used by version 1
|
|
|
|
*/
|
2010-08-22 06:37:53 -06:00
|
|
|
static inline int
|
2015-09-21 12:01:43 -06:00
|
|
|
ip_vs_conn_fill_param_sync(struct netns_ipvs *ipvs, int af, union ip_vs_sync_conn *sc,
|
2010-11-19 06:25:12 -07:00
|
|
|
struct ip_vs_conn_param *p,
|
|
|
|
__u8 *pe_data, unsigned int pe_data_len,
|
|
|
|
__u8 *pe_name, unsigned int pe_name_len)
|
2010-08-22 06:37:53 -06:00
|
|
|
{
|
2010-11-19 06:25:12 -07:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (af == AF_INET6)
|
2015-09-21 12:01:43 -06:00
|
|
|
ip_vs_conn_fill_param(ipvs, af, sc->v6.protocol,
|
2010-11-19 06:25:12 -07:00
|
|
|
(const union nf_inet_addr *)&sc->v6.caddr,
|
|
|
|
sc->v6.cport,
|
|
|
|
(const union nf_inet_addr *)&sc->v6.vaddr,
|
|
|
|
sc->v6.vport, p);
|
|
|
|
else
|
|
|
|
#endif
|
2015-09-21 12:01:43 -06:00
|
|
|
ip_vs_conn_fill_param(ipvs, af, sc->v4.protocol,
|
2010-11-19 06:25:12 -07:00
|
|
|
(const union nf_inet_addr *)&sc->v4.caddr,
|
|
|
|
sc->v4.cport,
|
|
|
|
(const union nf_inet_addr *)&sc->v4.vaddr,
|
|
|
|
sc->v4.vport, p);
|
|
|
|
/* Handle pe data */
|
|
|
|
if (pe_data_len) {
|
|
|
|
if (pe_name_len) {
|
|
|
|
char buff[IP_VS_PENAME_MAXLEN+1];
|
|
|
|
|
|
|
|
memcpy(buff, pe_name, pe_name_len);
|
|
|
|
buff[pe_name_len]=0;
|
|
|
|
p->pe = __ip_vs_pe_getbyname(buff);
|
|
|
|
if (!p->pe) {
|
2011-01-03 06:44:55 -07:00
|
|
|
IP_VS_DBG(3, "BACKUP, no %s engine found/loaded\n",
|
|
|
|
buff);
|
2010-11-19 06:25:12 -07:00
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
IP_VS_ERR_RL("BACKUP, Invalid PE parameters\n");
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2011-03-06 19:11:34 -07:00
|
|
|
p->pe_data = kmemdup(pe_data, pe_data_len, GFP_ATOMIC);
|
2010-11-19 06:25:12 -07:00
|
|
|
if (!p->pe_data) {
|
2014-11-18 12:37:05 -07:00
|
|
|
module_put(p->pe->module);
|
2010-11-19 06:25:12 -07:00
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
p->pe_data_len = pe_data_len;
|
|
|
|
}
|
2010-08-22 06:37:53 -06:00
|
|
|
return 0;
|
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/*
|
2010-11-19 06:25:12 -07:00
|
|
|
* Connection Add / Update.
|
|
|
|
* Common for version 0 and 1 reception of backup sync_conns.
|
|
|
|
* Param: ...
|
|
|
|
* timeout is in sec.
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
2015-09-21 12:02:18 -06:00
|
|
|
static void ip_vs_proc_conn(struct netns_ipvs *ipvs, struct ip_vs_conn_param *param,
|
2011-01-03 06:44:52 -07:00
|
|
|
unsigned int flags, unsigned int state,
|
|
|
|
unsigned int protocol, unsigned int type,
|
2010-11-19 06:25:12 -07:00
|
|
|
const union nf_inet_addr *daddr, __be16 dport,
|
|
|
|
unsigned long timeout, __u32 fwmark,
|
2011-01-03 06:44:52 -07:00
|
|
|
struct ip_vs_sync_conn_options *opt)
|
2010-11-19 06:25:12 -07:00
|
|
|
{
|
|
|
|
struct ip_vs_dest *dest;
|
|
|
|
struct ip_vs_conn *cp;
|
|
|
|
|
2015-02-23 11:02:34 -07:00
|
|
|
if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
|
2010-11-19 06:25:12 -07:00
|
|
|
cp = ip_vs_conn_in_get(param);
|
2015-02-23 11:02:34 -07:00
|
|
|
if (cp && ((cp->dport != dport) ||
|
|
|
|
!ip_vs_addr_equal(cp->daf, &cp->daddr, daddr))) {
|
|
|
|
if (!(flags & IP_VS_CONN_F_INACTIVE)) {
|
|
|
|
ip_vs_conn_expire_now(cp);
|
|
|
|
__ip_vs_conn_put(cp);
|
|
|
|
cp = NULL;
|
|
|
|
} else {
|
|
|
|
/* This is the expiration message for the
|
|
|
|
* connection that was already replaced, so we
|
|
|
|
* just ignore it.
|
|
|
|
*/
|
|
|
|
__ip_vs_conn_put(cp);
|
|
|
|
kfree(param->pe_data);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
} else {
|
2010-11-19 06:25:12 -07:00
|
|
|
cp = ip_vs_ct_in_get(param);
|
2015-02-23 11:02:34 -07:00
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
|
2012-04-24 14:46:38 -06:00
|
|
|
if (cp) {
|
|
|
|
/* Free pe_data */
|
2010-11-19 06:25:12 -07:00
|
|
|
kfree(param->pe_data);
|
2012-04-24 14:46:38 -06:00
|
|
|
|
|
|
|
dest = cp->dest;
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_lock_bh(&cp->lock);
|
2012-04-24 14:46:38 -06:00
|
|
|
if ((cp->flags ^ flags) & IP_VS_CONN_F_INACTIVE &&
|
|
|
|
!(flags & IP_VS_CONN_F_TEMPLATE) && dest) {
|
|
|
|
if (flags & IP_VS_CONN_F_INACTIVE) {
|
|
|
|
atomic_dec(&dest->activeconns);
|
|
|
|
atomic_inc(&dest->inactconns);
|
|
|
|
} else {
|
|
|
|
atomic_inc(&dest->activeconns);
|
|
|
|
atomic_dec(&dest->inactconns);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
flags &= IP_VS_CONN_F_BACKUP_UPD_MASK;
|
|
|
|
flags |= cp->flags & ~IP_VS_CONN_F_BACKUP_UPD_MASK;
|
|
|
|
cp->flags = flags;
|
2013-03-22 03:46:54 -06:00
|
|
|
spin_unlock_bh(&cp->lock);
|
2013-03-22 03:46:52 -06:00
|
|
|
if (!dest)
|
|
|
|
ip_vs_try_bind_dest(cp);
|
2012-04-24 14:46:38 -06:00
|
|
|
} else {
|
2010-11-19 06:25:12 -07:00
|
|
|
/*
|
|
|
|
* Find the appropriate destination for the connection.
|
|
|
|
* If it is not found the connection will remain unbound
|
|
|
|
* but still handled.
|
|
|
|
*/
|
2013-03-22 03:46:52 -06:00
|
|
|
rcu_read_lock();
|
2014-09-09 17:40:21 -06:00
|
|
|
/* This function is only invoked by the synchronization
|
|
|
|
* code. We do not currently support heterogeneous pools
|
|
|
|
* with synchronization, so we can make the assumption that
|
|
|
|
* the svc_af is the same as the dest_af
|
|
|
|
*/
|
2015-09-21 12:01:51 -06:00
|
|
|
dest = ip_vs_find_dest(ipvs, type, type, daddr, dport,
|
2014-09-09 17:40:21 -06:00
|
|
|
param->vaddr, param->vport, protocol,
|
|
|
|
fwmark, flags);
|
2010-11-19 06:25:12 -07:00
|
|
|
|
2014-09-09 17:40:23 -06:00
|
|
|
cp = ip_vs_conn_new(param, type, daddr, dport, flags, dest,
|
|
|
|
fwmark);
|
2013-03-22 03:46:52 -06:00
|
|
|
rcu_read_unlock();
|
2010-11-19 06:25:12 -07:00
|
|
|
if (!cp) {
|
2014-06-20 14:35:42 -06:00
|
|
|
kfree(param->pe_data);
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_DBG(2, "BACKUP, add new conn. failed\n");
|
|
|
|
return;
|
|
|
|
}
|
2015-02-21 12:03:10 -07:00
|
|
|
if (!(flags & IP_VS_CONN_F_TEMPLATE))
|
|
|
|
kfree(param->pe_data);
|
2010-11-19 06:25:12 -07:00
|
|
|
}
|
|
|
|
|
netfilter: ip_vs_sync: fix bogus maybe-uninitialized warning
Building the ip_vs_sync code with CONFIG_OPTIMIZE_INLINING on x86
confuses the compiler to the point where it produces a rather
dubious warning message:
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘opt.init_seq’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
struct ip_vs_sync_conn_options opt;
^~~
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘opt.delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘opt.previous_delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘*((void *)&opt+12).init_seq’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘*((void *)&opt+12).delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/netfilter/ipvs/ip_vs_sync.c:1073:33: error: ‘*((void *)&opt+12).previous_delta’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
The problem appears to be a combination of a number of factors, including
the __builtin_bswap32 compiler builtin being slightly odd, having a large
amount of code inlined into a single function, and the way that some
functions only get partially inlined here.
I've spent way too much time trying to work out a way to improve the
code, but the best I've come up with is to add an explicit memset
right before the ip_vs_seq structure is first initialized here. When
the compiler works correctly, this has absolutely no effect, but in the
case that produces the warning, the warning disappears.
In the process of analysing this warning, I also noticed that
we use memcpy to copy the larger ip_vs_sync_conn_options structure
over two members of the ip_vs_conn structure. This works because
the layout is identical, but seems error-prone, so I'm changing
this in the process to directly copy the two members. This change
seemed to have no effect on the object code or the warning, but
it deals with the same data, so I kept the two changes together.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-24 09:34:32 -06:00
|
|
|
if (opt) {
|
|
|
|
cp->in_seq = opt->in_seq;
|
|
|
|
cp->out_seq = opt->out_seq;
|
|
|
|
}
|
2011-02-04 02:33:01 -07:00
|
|
|
atomic_set(&cp->in_pkts, sysctl_sync_threshold(ipvs));
|
2010-11-19 06:25:12 -07:00
|
|
|
cp->state = state;
|
|
|
|
cp->old_state = cp->state;
|
|
|
|
/*
|
|
|
|
* For Ver 0 messages style
|
|
|
|
* - Not possible to recover the right timeout for templates
|
|
|
|
* - can not find the right fwmark
|
|
|
|
* virtual service. If needed, we can do it for
|
|
|
|
* non-fwmark persistent services.
|
|
|
|
* Ver 1 messages style.
|
|
|
|
* - No problem.
|
|
|
|
*/
|
|
|
|
if (timeout) {
|
|
|
|
if (timeout > MAX_SCHEDULE_TIMEOUT / HZ)
|
|
|
|
timeout = MAX_SCHEDULE_TIMEOUT / HZ;
|
|
|
|
cp->timeout = timeout*HZ;
|
2011-01-03 06:44:52 -07:00
|
|
|
} else {
|
|
|
|
struct ip_vs_proto_data *pd;
|
|
|
|
|
2015-09-21 12:02:01 -06:00
|
|
|
pd = ip_vs_proto_data_get(ipvs, protocol);
|
2011-01-03 06:44:52 -07:00
|
|
|
if (!(flags & IP_VS_CONN_F_TEMPLATE) && pd && pd->timeout_table)
|
|
|
|
cp->timeout = pd->timeout_table[state];
|
|
|
|
else
|
|
|
|
cp->timeout = (3*60*HZ);
|
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
ip_vs_conn_put(cp);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Process received multicast message for Version 0
|
|
|
|
*/
|
2015-09-21 12:01:43 -06:00
|
|
|
static void ip_vs_process_message_v0(struct netns_ipvs *ipvs, const char *buffer,
|
2011-01-03 06:44:52 -07:00
|
|
|
const size_t buflen)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-11-19 06:25:13 -07:00
|
|
|
struct ip_vs_sync_mesg_v0 *m = (struct ip_vs_sync_mesg_v0 *)buffer;
|
2010-11-19 06:25:11 -07:00
|
|
|
struct ip_vs_sync_conn_v0 *s;
|
2005-04-16 16:20:36 -06:00
|
|
|
struct ip_vs_sync_conn_options *opt;
|
2007-10-29 05:35:45 -06:00
|
|
|
struct ip_vs_protocol *pp;
|
2010-08-22 06:37:52 -06:00
|
|
|
struct ip_vs_conn_param param;
|
2005-04-16 16:20:36 -06:00
|
|
|
char *p;
|
|
|
|
int i;
|
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
p = (char *)buffer + sizeof(struct ip_vs_sync_mesg_v0);
|
2005-04-16 16:20:36 -06:00
|
|
|
for (i=0; i<m->nr_conns; i++) {
|
2012-04-14 23:58:06 -06:00
|
|
|
unsigned int flags, state;
|
2005-09-14 22:08:51 -06:00
|
|
|
|
2008-04-29 04:21:23 -06:00
|
|
|
if (p + SIMPLE_CONN_SIZE > buffer+buflen) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_ERR_RL("BACKUP v0, bogus conn\n");
|
2008-04-29 04:21:23 -06:00
|
|
|
return;
|
|
|
|
}
|
2010-11-19 06:25:11 -07:00
|
|
|
s = (struct ip_vs_sync_conn_v0 *) p;
|
2007-11-19 22:52:42 -07:00
|
|
|
flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC;
|
2008-04-29 04:21:23 -06:00
|
|
|
flags &= ~IP_VS_CONN_F_HASHED;
|
|
|
|
if (flags & IP_VS_CONN_F_SEQ_MASK) {
|
|
|
|
opt = (struct ip_vs_sync_conn_options *)&s[1];
|
|
|
|
p += FULL_CONN_SIZE;
|
|
|
|
if (p > buffer+buflen) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_ERR_RL("BACKUP v0, Dropping buffer bogus conn options\n");
|
2008-04-29 04:21:23 -06:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
opt = NULL;
|
|
|
|
p += SIMPLE_CONN_SIZE;
|
|
|
|
}
|
|
|
|
|
2007-11-19 22:53:27 -07:00
|
|
|
state = ntohs(s->state);
|
2008-04-29 04:21:23 -06:00
|
|
|
if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
|
|
|
|
pp = ip_vs_proto_get(s->protocol);
|
|
|
|
if (!pp) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_DBG(2, "BACKUP v0, Unsupported protocol %u\n",
|
2008-04-29 04:21:23 -06:00
|
|
|
s->protocol);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if (state >= pp->num_states) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_DBG(2, "BACKUP v0, Invalid %s state %u\n",
|
2008-04-29 04:21:23 -06:00
|
|
|
pp->name, state);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
} else {
|
2018-07-05 23:25:53 -06:00
|
|
|
if (state >= IP_VS_CTPL_S_LAST)
|
|
|
|
IP_VS_DBG(7, "BACKUP v0, Invalid tpl state %u\n",
|
|
|
|
state);
|
2008-04-29 04:21:23 -06:00
|
|
|
}
|
|
|
|
|
2015-09-21 12:01:43 -06:00
|
|
|
ip_vs_conn_fill_param(ipvs, AF_INET, s->protocol,
|
2010-11-19 06:25:12 -07:00
|
|
|
(const union nf_inet_addr *)&s->caddr,
|
|
|
|
s->cport,
|
|
|
|
(const union nf_inet_addr *)&s->vaddr,
|
|
|
|
s->vport, ¶m);
|
|
|
|
|
|
|
|
/* Send timeout as Zero */
|
2015-09-21 12:02:18 -06:00
|
|
|
ip_vs_proc_conn(ipvs, ¶m, flags, state, s->protocol, AF_INET,
|
2010-11-19 06:25:12 -07:00
|
|
|
(union nf_inet_addr *)&s->daddr, s->dport,
|
2011-01-03 06:44:52 -07:00
|
|
|
0, 0, opt);
|
2010-11-19 06:25:12 -07:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Handle options
|
|
|
|
*/
|
|
|
|
static inline int ip_vs_proc_seqopt(__u8 *p, unsigned int plen,
|
|
|
|
__u32 *opt_flags,
|
|
|
|
struct ip_vs_sync_conn_options *opt)
|
|
|
|
{
|
|
|
|
struct ip_vs_sync_conn_options *topt;
|
|
|
|
|
|
|
|
topt = (struct ip_vs_sync_conn_options *)p;
|
|
|
|
|
|
|
|
if (plen != sizeof(struct ip_vs_sync_conn_options)) {
|
|
|
|
IP_VS_DBG(2, "BACKUP, bogus conn options length\n");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
if (*opt_flags & IPVS_OPT_F_SEQ_DATA) {
|
|
|
|
IP_VS_DBG(2, "BACKUP, conn options found twice\n");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
ntoh_seq(&topt->in_seq, &opt->in_seq);
|
|
|
|
ntoh_seq(&topt->out_seq, &opt->out_seq);
|
|
|
|
*opt_flags |= IPVS_OPT_F_SEQ_DATA;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int ip_vs_proc_str(__u8 *p, unsigned int plen, unsigned int *data_len,
|
|
|
|
__u8 **data, unsigned int maxlen,
|
|
|
|
__u32 *opt_flags, __u32 flag)
|
|
|
|
{
|
|
|
|
if (plen > maxlen) {
|
|
|
|
IP_VS_DBG(2, "BACKUP, bogus par.data len > %d\n", maxlen);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
if (*opt_flags & flag) {
|
|
|
|
IP_VS_DBG(2, "BACKUP, Par.data found twice 0x%x\n", flag);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
*data_len = plen;
|
|
|
|
*data = p;
|
|
|
|
*opt_flags |= flag;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* Process a Version 1 sync. connection
|
|
|
|
*/
|
2015-09-21 12:02:19 -06:00
|
|
|
static inline int ip_vs_proc_sync_conn(struct netns_ipvs *ipvs, __u8 *p, __u8 *msg_end)
|
2010-11-19 06:25:12 -07:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_conn_options opt;
|
|
|
|
union ip_vs_sync_conn *s;
|
|
|
|
struct ip_vs_protocol *pp;
|
|
|
|
struct ip_vs_conn_param param;
|
|
|
|
__u32 flags;
|
|
|
|
unsigned int af, state, pe_data_len=0, pe_name_len=0;
|
|
|
|
__u8 *pe_data=NULL, *pe_name=NULL;
|
|
|
|
__u32 opt_flags=0;
|
|
|
|
int retc=0;
|
|
|
|
|
|
|
|
s = (union ip_vs_sync_conn *) p;
|
|
|
|
|
|
|
|
if (s->v6.type & STYPE_F_INET6) {
|
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
af = AF_INET6;
|
|
|
|
p += sizeof(struct ip_vs_sync_v6);
|
|
|
|
#else
|
|
|
|
IP_VS_DBG(3,"BACKUP, IPv6 msg received, and IPVS is not compiled for IPv6\n");
|
|
|
|
retc = 10;
|
|
|
|
goto out;
|
|
|
|
#endif
|
|
|
|
} else if (!s->v4.type) {
|
|
|
|
af = AF_INET;
|
|
|
|
p += sizeof(struct ip_vs_sync_v4);
|
|
|
|
} else {
|
|
|
|
return -10;
|
|
|
|
}
|
|
|
|
if (p > msg_end)
|
|
|
|
return -20;
|
|
|
|
|
|
|
|
/* Process optional params check Type & Len. */
|
|
|
|
while (p < msg_end) {
|
|
|
|
int ptype;
|
|
|
|
int plen;
|
|
|
|
|
|
|
|
if (p+2 > msg_end)
|
|
|
|
return -30;
|
|
|
|
ptype = *(p++);
|
|
|
|
plen = *(p++);
|
|
|
|
|
|
|
|
if (!plen || ((p + plen) > msg_end))
|
|
|
|
return -40;
|
|
|
|
/* Handle seq option p = param data */
|
|
|
|
switch (ptype & ~IPVS_OPT_F_PARAM) {
|
|
|
|
case IPVS_OPT_SEQ_DATA:
|
|
|
|
if (ip_vs_proc_seqopt(p, plen, &opt_flags, &opt))
|
|
|
|
return -50;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case IPVS_OPT_PE_DATA:
|
|
|
|
if (ip_vs_proc_str(p, plen, &pe_data_len, &pe_data,
|
|
|
|
IP_VS_PEDATA_MAXLEN, &opt_flags,
|
|
|
|
IPVS_OPT_F_PE_DATA))
|
|
|
|
return -60;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case IPVS_OPT_PE_NAME:
|
|
|
|
if (ip_vs_proc_str(p, plen,&pe_name_len, &pe_name,
|
|
|
|
IP_VS_PENAME_MAXLEN, &opt_flags,
|
|
|
|
IPVS_OPT_F_PE_NAME))
|
|
|
|
return -70;
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
/* Param data mandatory ? */
|
|
|
|
if (!(ptype & IPVS_OPT_F_PARAM)) {
|
|
|
|
IP_VS_DBG(3, "BACKUP, Unknown mandatory param %d found\n",
|
|
|
|
ptype & ~IPVS_OPT_F_PARAM);
|
|
|
|
retc = 20;
|
|
|
|
goto out;
|
|
|
|
}
|
2010-08-22 06:37:52 -06:00
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
p += plen; /* Next option */
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Get flags and Mask off unsupported */
|
|
|
|
flags = ntohl(s->v4.flags) & IP_VS_CONN_F_BACKUP_MASK;
|
|
|
|
flags |= IP_VS_CONN_F_SYNC;
|
|
|
|
state = ntohs(s->v4.state);
|
|
|
|
|
|
|
|
if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
|
|
|
|
pp = ip_vs_proto_get(s->v4.protocol);
|
|
|
|
if (!pp) {
|
|
|
|
IP_VS_DBG(3,"BACKUP, Unsupported protocol %u\n",
|
|
|
|
s->v4.protocol);
|
|
|
|
retc = 30;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
if (state >= pp->num_states) {
|
|
|
|
IP_VS_DBG(3, "BACKUP, Invalid %s state %u\n",
|
|
|
|
pp->name, state);
|
|
|
|
retc = 40;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
} else {
|
2018-07-05 23:25:53 -06:00
|
|
|
if (state >= IP_VS_CTPL_S_LAST)
|
|
|
|
IP_VS_DBG(7, "BACKUP, Invalid tpl state %u\n",
|
|
|
|
state);
|
2010-11-19 06:25:12 -07:00
|
|
|
}
|
2015-09-21 12:02:18 -06:00
|
|
|
if (ip_vs_conn_fill_param_sync(ipvs, af, s, ¶m, pe_data,
|
2011-01-03 06:44:57 -07:00
|
|
|
pe_data_len, pe_name, pe_name_len)) {
|
2010-11-19 06:25:12 -07:00
|
|
|
retc = 50;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
/* If only IPv4, just silent skip IPv6 */
|
|
|
|
if (af == AF_INET)
|
2015-09-21 12:02:18 -06:00
|
|
|
ip_vs_proc_conn(ipvs, ¶m, flags, state, s->v4.protocol, af,
|
2010-11-19 06:25:12 -07:00
|
|
|
(union nf_inet_addr *)&s->v4.daddr, s->v4.dport,
|
|
|
|
ntohl(s->v4.timeout), ntohl(s->v4.fwmark),
|
2011-01-03 06:44:52 -07:00
|
|
|
(opt_flags & IPVS_OPT_F_SEQ_DATA ? &opt : NULL)
|
|
|
|
);
|
2010-11-19 06:25:12 -07:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
else
|
2015-09-21 12:02:18 -06:00
|
|
|
ip_vs_proc_conn(ipvs, ¶m, flags, state, s->v6.protocol, af,
|
2010-11-19 06:25:12 -07:00
|
|
|
(union nf_inet_addr *)&s->v6.daddr, s->v6.dport,
|
|
|
|
ntohl(s->v6.timeout), ntohl(s->v6.fwmark),
|
2011-01-03 06:44:52 -07:00
|
|
|
(opt_flags & IPVS_OPT_F_SEQ_DATA ? &opt : NULL)
|
|
|
|
);
|
2010-11-19 06:25:12 -07:00
|
|
|
#endif
|
2015-02-21 12:03:10 -07:00
|
|
|
ip_vs_pe_put(param.pe);
|
2010-11-19 06:25:12 -07:00
|
|
|
return 0;
|
|
|
|
/* Error exit */
|
|
|
|
out:
|
|
|
|
IP_VS_DBG(2, "BACKUP, Single msg dropped err:%d\n", retc);
|
|
|
|
return retc;
|
|
|
|
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* Process received multicast message and create the corresponding
|
|
|
|
* ip_vs_conn entries.
|
|
|
|
* Handles Version 0 & 1
|
|
|
|
*/
|
2015-09-21 12:02:15 -06:00
|
|
|
static void ip_vs_process_message(struct netns_ipvs *ipvs, __u8 *buffer,
|
2011-01-03 06:44:52 -07:00
|
|
|
const size_t buflen)
|
2010-11-19 06:25:12 -07:00
|
|
|
{
|
2010-11-19 06:25:13 -07:00
|
|
|
struct ip_vs_sync_mesg *m2 = (struct ip_vs_sync_mesg *)buffer;
|
2010-11-19 06:25:12 -07:00
|
|
|
__u8 *p, *msg_end;
|
2010-11-19 06:25:13 -07:00
|
|
|
int i, nr_conns;
|
2010-11-19 06:25:12 -07:00
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
if (buflen < sizeof(struct ip_vs_sync_mesg_v0)) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_DBG(2, "BACKUP, message header too short\n");
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2013-04-18 19:43:44 -06:00
|
|
|
if (buflen != ntohs(m2->size)) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_DBG(2, "BACKUP, bogus message size\n");
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
/* SyncID sanity check */
|
2015-07-26 06:03:27 -06:00
|
|
|
if (ipvs->bcfg.syncid != 0 && m2->syncid != ipvs->bcfg.syncid) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_DBG(7, "BACKUP, Ignoring syncid = %d\n", m2->syncid);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
/* Handle version 1 message */
|
|
|
|
if ((m2->version == SYNC_PROTO_VER) && (m2->reserved == 0)
|
|
|
|
&& (m2->spare == 0)) {
|
|
|
|
|
2010-11-19 06:25:13 -07:00
|
|
|
msg_end = buffer + sizeof(struct ip_vs_sync_mesg);
|
2010-11-19 06:25:12 -07:00
|
|
|
nr_conns = m2->nr_conns;
|
|
|
|
|
|
|
|
for (i=0; i<nr_conns; i++) {
|
|
|
|
union ip_vs_sync_conn *s;
|
2012-04-14 23:58:06 -06:00
|
|
|
unsigned int size;
|
2010-11-19 06:25:12 -07:00
|
|
|
int retc;
|
|
|
|
|
|
|
|
p = msg_end;
|
|
|
|
if (p + sizeof(s->v4) > buffer+buflen) {
|
|
|
|
IP_VS_ERR_RL("BACKUP, Dropping buffer, to small\n");
|
|
|
|
return;
|
2007-11-19 22:53:27 -07:00
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
s = (union ip_vs_sync_conn *)p;
|
|
|
|
size = ntohs(s->v4.ver_size) & SVER_MASK;
|
|
|
|
msg_end = p + size;
|
|
|
|
/* Basic sanity checks */
|
|
|
|
if (msg_end > buffer+buflen) {
|
|
|
|
IP_VS_ERR_RL("BACKUP, Dropping buffer, msg > buffer\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
return;
|
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
if (ntohs(s->v4.ver_size) >> SVER_SHIFT) {
|
|
|
|
IP_VS_ERR_RL("BACKUP, Dropping buffer, Unknown version %d\n",
|
|
|
|
ntohs(s->v4.ver_size) >> SVER_SHIFT);
|
|
|
|
return;
|
2007-11-19 22:53:27 -07:00
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
/* Process a single sync_conn */
|
2015-09-21 12:02:19 -06:00
|
|
|
retc = ip_vs_proc_sync_conn(ipvs, p, msg_end);
|
2011-01-03 06:44:52 -07:00
|
|
|
if (retc < 0) {
|
2010-11-19 06:25:12 -07:00
|
|
|
IP_VS_ERR_RL("BACKUP, Dropping buffer, Err: %d in decoding\n",
|
|
|
|
retc);
|
|
|
|
return;
|
2010-02-18 04:31:05 -07:00
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
/* Make sure we have 32 bit alignment */
|
|
|
|
msg_end = p + ((size + 3) & ~3);
|
2007-11-19 22:53:27 -07:00
|
|
|
}
|
2010-11-19 06:25:12 -07:00
|
|
|
} else {
|
|
|
|
/* Old type of message */
|
2015-09-21 12:01:43 -06:00
|
|
|
ip_vs_process_message_v0(ipvs, buffer, buflen);
|
2010-11-19 06:25:12 -07:00
|
|
|
return;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2012-05-08 11:39:49 -06:00
|
|
|
/*
|
|
|
|
* Setup sndbuf (mode=1) or rcvbuf (mode=0)
|
|
|
|
*/
|
|
|
|
static void set_sock_size(struct sock *sk, int mode, int val)
|
|
|
|
{
|
|
|
|
/* setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &val, sizeof(val)); */
|
|
|
|
/* setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)); */
|
|
|
|
lock_sock(sk);
|
|
|
|
if (mode) {
|
|
|
|
val = clamp_t(int, val, (SOCK_MIN_SNDBUF + 1) / 2,
|
|
|
|
sysctl_wmem_max);
|
|
|
|
sk->sk_sndbuf = val * 2;
|
|
|
|
sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
|
|
|
|
} else {
|
|
|
|
val = clamp_t(int, val, (SOCK_MIN_RCVBUF + 1) / 2,
|
|
|
|
sysctl_rmem_max);
|
|
|
|
sk->sk_rcvbuf = val * 2;
|
|
|
|
sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
|
|
|
|
}
|
|
|
|
release_sock(sk);
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* Setup loopback of outgoing multicasts on a sending socket
|
|
|
|
*/
|
|
|
|
static void set_mcast_loop(struct sock *sk, u_char loop)
|
|
|
|
{
|
|
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
|
|
|
|
/* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
|
|
|
|
lock_sock(sk);
|
|
|
|
inet->mc_loop = loop ? 1 : 0;
|
2015-07-26 06:03:28 -06:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (sk->sk_family == AF_INET6) {
|
|
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
|
|
|
|
|
|
/* IPV6_MULTICAST_LOOP */
|
|
|
|
np->mc_loop = loop ? 1 : 0;
|
|
|
|
}
|
|
|
|
#endif
|
2005-04-16 16:20:36 -06:00
|
|
|
release_sock(sk);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Specify TTL for outgoing multicasts on a sending socket
|
|
|
|
*/
|
|
|
|
static void set_mcast_ttl(struct sock *sk, u_char ttl)
|
|
|
|
{
|
|
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
|
|
|
|
/* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
|
|
|
|
lock_sock(sk);
|
|
|
|
inet->mc_ttl = ttl;
|
2015-07-26 06:03:28 -06:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (sk->sk_family == AF_INET6) {
|
|
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
|
|
|
|
|
|
/* IPV6_MULTICAST_HOPS */
|
|
|
|
np->mcast_hops = ttl;
|
|
|
|
}
|
|
|
|
#endif
|
2005-04-16 16:20:36 -06:00
|
|
|
release_sock(sk);
|
|
|
|
}
|
|
|
|
|
2015-07-26 06:03:27 -06:00
|
|
|
/* Control fragmentation of messages */
|
|
|
|
static void set_mcast_pmtudisc(struct sock *sk, int val)
|
|
|
|
{
|
|
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
|
|
|
|
/* setsockopt(sock, SOL_IP, IP_MTU_DISCOVER, &val, sizeof(val)); */
|
|
|
|
lock_sock(sk);
|
|
|
|
inet->pmtudisc = val;
|
2015-07-26 06:03:28 -06:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (sk->sk_family == AF_INET6) {
|
|
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
|
|
|
|
|
|
/* IPV6_MTU_DISCOVER */
|
|
|
|
np->pmtudisc = val;
|
|
|
|
}
|
|
|
|
#endif
|
2015-07-26 06:03:27 -06:00
|
|
|
release_sock(sk);
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* Specifiy default interface for outgoing multicasts
|
|
|
|
*/
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
static int set_mcast_if(struct sock *sk, struct net_device *dev)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
|
|
|
|
if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
lock_sock(sk);
|
|
|
|
inet->mc_index = dev->ifindex;
|
|
|
|
/* inet->mc_addr = 0; */
|
2015-07-26 06:03:28 -06:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (sk->sk_family == AF_INET6) {
|
|
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
|
|
|
|
|
|
/* IPV6_MULTICAST_IF */
|
|
|
|
np->mcast_oif = dev->ifindex;
|
|
|
|
}
|
|
|
|
#endif
|
2005-04-16 16:20:36 -06:00
|
|
|
release_sock(sk);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Join a multicast group.
|
|
|
|
* the group is specified by a class D multicast address 224.0.0.0/8
|
|
|
|
* in the in_addr structure passed in as a parameter.
|
|
|
|
*/
|
|
|
|
static int
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
join_mcast_group(struct sock *sk, struct in_addr *addr, struct net_device *dev)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
struct ip_mreqn mreq;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
memset(&mreq, 0, sizeof(mreq));
|
|
|
|
memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
|
|
|
|
|
|
|
|
if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
mreq.imr_ifindex = dev->ifindex;
|
|
|
|
|
|
|
|
lock_sock(sk);
|
|
|
|
ret = ip_mc_join_group(sk, &mreq);
|
|
|
|
release_sock(sk);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
static int join_mcast_group6(struct sock *sk, struct in6_addr *addr,
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
struct net_device *dev)
|
2015-07-26 06:03:28 -06:00
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
lock_sock(sk);
|
|
|
|
ret = ipv6_sock_mc_join(sk, dev->ifindex, addr);
|
|
|
|
release_sock(sk);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
#endif
|
2005-04-16 16:20:36 -06:00
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
static int bind_mcastif_addr(struct socket *sock, struct net_device *dev)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2006-09-26 22:27:54 -06:00
|
|
|
__be32 addr;
|
2005-04-16 16:20:36 -06:00
|
|
|
struct sockaddr_in sin;
|
|
|
|
|
|
|
|
addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
|
|
|
|
if (!addr)
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("You probably need to specify IP address on "
|
|
|
|
"multicast interface.\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-10-31 01:54:29 -06:00
|
|
|
IP_VS_DBG(7, "binding socket with (%s) %pI4\n",
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
dev->name, &addr);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* Now bind the socket with the address of multicast interface */
|
|
|
|
sin.sin_family = AF_INET;
|
|
|
|
sin.sin_addr.s_addr = addr;
|
|
|
|
sin.sin_port = 0;
|
|
|
|
|
|
|
|
return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
|
|
|
|
}
|
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
static void get_mcast_sockaddr(union ipvs_sockaddr *sa, int *salen,
|
|
|
|
struct ipvs_sync_daemon_cfg *c, int id)
|
|
|
|
{
|
|
|
|
if (AF_INET6 == c->mcast_af) {
|
|
|
|
sa->in6 = (struct sockaddr_in6) {
|
|
|
|
.sin6_family = AF_INET6,
|
|
|
|
.sin6_port = htons(c->mcast_port + id),
|
|
|
|
};
|
|
|
|
sa->in6.sin6_addr = c->mcast_group.in6;
|
|
|
|
*salen = sizeof(sa->in6);
|
|
|
|
} else {
|
|
|
|
sa->in = (struct sockaddr_in) {
|
|
|
|
.sin_family = AF_INET,
|
|
|
|
.sin_port = htons(c->mcast_port + id),
|
|
|
|
};
|
|
|
|
sa->in.sin_addr = c->mcast_group.in;
|
|
|
|
*salen = sizeof(sa->in);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* Set up sending multicast socket over UDP
|
|
|
|
*/
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
static int make_send_sock(struct netns_ipvs *ipvs, int id,
|
|
|
|
struct net_device *dev, struct socket **sock_ret)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2012-05-08 11:40:30 -06:00
|
|
|
/* multicast addr */
|
2015-07-26 06:03:28 -06:00
|
|
|
union ipvs_sockaddr mcast_addr;
|
2005-04-16 16:20:36 -06:00
|
|
|
struct socket *sock;
|
2015-07-26 06:03:28 -06:00
|
|
|
int result, salen;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2015-05-08 20:10:31 -06:00
|
|
|
/* First create a socket */
|
2015-09-21 12:02:12 -06:00
|
|
|
result = sock_create_kern(ipvs->net, ipvs->mcfg.mcast_af, SOCK_DGRAM,
|
2015-07-26 06:03:28 -06:00
|
|
|
IPPROTO_UDP, &sock);
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error during creation of socket; terminating\n");
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto error;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
*sock_ret = sock;
|
|
|
|
result = set_mcast_if(sock->sk, dev);
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error setting outbound mcast interface\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
|
|
|
|
set_mcast_loop(sock->sk, 0);
|
2015-07-26 06:03:28 -06:00
|
|
|
set_mcast_ttl(sock->sk, ipvs->mcfg.mcast_ttl);
|
2015-07-26 06:03:27 -06:00
|
|
|
/* Allow fragmentation if MTU changes */
|
|
|
|
set_mcast_pmtudisc(sock->sk, IP_PMTUDISC_DONT);
|
2012-05-08 11:39:49 -06:00
|
|
|
result = sysctl_sync_sock_size(ipvs);
|
|
|
|
if (result > 0)
|
|
|
|
set_sock_size(sock->sk, 1, result);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
if (AF_INET == ipvs->mcfg.mcast_af)
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = bind_mcastif_addr(sock, dev);
|
2015-07-26 06:03:28 -06:00
|
|
|
else
|
|
|
|
result = 0;
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error binding address of the mcast interface\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->mcfg, id);
|
2008-07-16 05:13:43 -06:00
|
|
|
result = sock->ops->connect(sock, (struct sockaddr *) &mcast_addr,
|
2015-07-26 06:03:28 -06:00
|
|
|
salen, 0);
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error connecting to the multicast addr\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-05-03 14:09:30 -06:00
|
|
|
error:
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
return result;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Set up receiving multicast socket over UDP
|
|
|
|
*/
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
static int make_receive_sock(struct netns_ipvs *ipvs, int id,
|
|
|
|
struct net_device *dev, struct socket **sock_ret)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2012-05-08 11:40:30 -06:00
|
|
|
/* multicast addr */
|
2015-07-26 06:03:28 -06:00
|
|
|
union ipvs_sockaddr mcast_addr;
|
2005-04-16 16:20:36 -06:00
|
|
|
struct socket *sock;
|
2015-07-26 06:03:28 -06:00
|
|
|
int result, salen;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* First create a socket */
|
2015-09-21 12:02:13 -06:00
|
|
|
result = sock_create_kern(ipvs->net, ipvs->bcfg.mcast_af, SOCK_DGRAM,
|
2015-07-26 06:03:28 -06:00
|
|
|
IPPROTO_UDP, &sock);
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error during creation of socket; terminating\n");
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto error;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
*sock_ret = sock;
|
2005-04-16 16:20:36 -06:00
|
|
|
/* it is equivalent to the REUSEADDR option in user-space */
|
2012-04-18 21:39:36 -06:00
|
|
|
sock->sk->sk_reuse = SK_CAN_REUSE;
|
2012-05-08 11:39:49 -06:00
|
|
|
result = sysctl_sync_sock_size(ipvs);
|
|
|
|
if (result > 0)
|
|
|
|
set_sock_size(sock->sk, 0, result);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id);
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
sock->sk->sk_bound_dev_if = dev->ifindex;
|
2015-07-26 06:03:28 -06:00
|
|
|
result = sock->ops->bind(sock, (struct sockaddr *)&mcast_addr, salen);
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error binding to the multicast addr\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* join the multicast group */
|
2015-07-26 06:03:28 -06:00
|
|
|
#ifdef CONFIG_IP_VS_IPV6
|
|
|
|
if (ipvs->bcfg.mcast_af == AF_INET6)
|
|
|
|
result = join_mcast_group6(sock->sk, &mcast_addr.in6.sin6_addr,
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
dev);
|
2015-07-26 06:03:28 -06:00
|
|
|
else
|
|
|
|
#endif
|
|
|
|
result = join_mcast_group(sock->sk, &mcast_addr.in.sin_addr,
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
dev);
|
2008-07-16 05:13:43 -06:00
|
|
|
if (result < 0) {
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_err("Error joining to the multicast group\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-05-03 14:09:30 -06:00
|
|
|
error:
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
return result;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
|
|
|
|
{
|
|
|
|
struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
|
|
|
|
struct kvec iov;
|
|
|
|
int len;
|
|
|
|
|
|
|
|
EnterFunction(7);
|
|
|
|
iov.iov_base = (void *)buffer;
|
|
|
|
iov.iov_len = length;
|
|
|
|
|
|
|
|
len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
|
|
|
|
|
|
|
|
LeaveFunction(7);
|
|
|
|
return len;
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:39:49 -06:00
|
|
|
static int
|
2005-04-16 16:20:36 -06:00
|
|
|
ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
|
|
|
|
{
|
|
|
|
int msize;
|
2012-05-08 11:39:49 -06:00
|
|
|
int ret;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2013-04-18 19:43:44 -06:00
|
|
|
msize = ntohs(msg->size);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2012-05-08 11:39:49 -06:00
|
|
|
ret = ip_vs_send_async(sock, (char *)msg, msize);
|
|
|
|
if (ret >= 0 || ret == -EAGAIN)
|
|
|
|
return ret;
|
|
|
|
pr_err("ip_vs_send_async error %d\n", ret);
|
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
|
|
|
|
{
|
|
|
|
struct msghdr msg = {NULL,};
|
2017-09-20 18:14:51 -06:00
|
|
|
struct kvec iov = {buffer, buflen};
|
2005-04-16 16:20:36 -06:00
|
|
|
int len;
|
|
|
|
|
|
|
|
EnterFunction(7);
|
|
|
|
|
|
|
|
/* Receive a packet */
|
2018-10-19 17:57:56 -06:00
|
|
|
iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, buflen);
|
2017-09-20 18:14:51 -06:00
|
|
|
len = sock_recvmsg(sock, &msg, MSG_DONTWAIT);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (len < 0)
|
2012-05-08 11:40:30 -06:00
|
|
|
return len;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
LeaveFunction(7);
|
|
|
|
return len;
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:39:49 -06:00
|
|
|
/* Wakeup the master thread for sending */
|
|
|
|
static void master_wakeup_work_handler(struct work_struct *work)
|
|
|
|
{
|
2012-05-08 11:40:30 -06:00
|
|
|
struct ipvs_master_sync_state *ms =
|
|
|
|
container_of(work, struct ipvs_master_sync_state,
|
|
|
|
master_wakeup_work.work);
|
|
|
|
struct netns_ipvs *ipvs = ms->ipvs;
|
2012-05-08 11:39:49 -06:00
|
|
|
|
|
|
|
spin_lock_bh(&ipvs->sync_lock);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (ms->sync_queue_len &&
|
|
|
|
ms->sync_queue_delay < IPVS_SYNC_WAKEUP_RATE) {
|
|
|
|
ms->sync_queue_delay = IPVS_SYNC_WAKEUP_RATE;
|
|
|
|
wake_up_process(ms->master_thread);
|
2012-05-08 11:39:49 -06:00
|
|
|
}
|
|
|
|
spin_unlock_bh(&ipvs->sync_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Get next buffer to send */
|
|
|
|
static inline struct ip_vs_sync_buff *
|
2012-05-08 11:40:30 -06:00
|
|
|
next_sync_buff(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms)
|
2012-05-08 11:39:49 -06:00
|
|
|
{
|
|
|
|
struct ip_vs_sync_buff *sb;
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
sb = sb_dequeue(ipvs, ms);
|
2012-05-08 11:39:49 -06:00
|
|
|
if (sb)
|
|
|
|
return sb;
|
|
|
|
/* Do not delay entries in buffer for more than 2 seconds */
|
2012-05-08 11:40:30 -06:00
|
|
|
return get_curr_sync_buff(ipvs, ms, IPVS_SYNC_FLUSH_TIME);
|
2012-05-08 11:39:49 -06:00
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
static int sync_thread_master(void *data)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2008-07-16 05:13:50 -06:00
|
|
|
struct ip_vs_sync_thread_data *tinfo = data;
|
2015-09-21 12:02:14 -06:00
|
|
|
struct netns_ipvs *ipvs = tinfo->ipvs;
|
2012-05-08 11:40:30 -06:00
|
|
|
struct ipvs_master_sync_state *ms = &ipvs->ms[tinfo->id];
|
2012-05-08 11:39:49 -06:00
|
|
|
struct sock *sk = tinfo->sock->sk;
|
2005-04-16 16:20:36 -06:00
|
|
|
struct ip_vs_sync_buff *sb;
|
|
|
|
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_info("sync thread started: state = MASTER, mcast_ifn = %s, "
|
2012-05-08 11:40:30 -06:00
|
|
|
"syncid = %d, id = %d\n",
|
2015-07-26 06:03:27 -06:00
|
|
|
ipvs->mcfg.mcast_ifn, ipvs->mcfg.syncid, tinfo->id);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2012-05-08 11:39:49 -06:00
|
|
|
for (;;) {
|
2012-05-08 11:40:30 -06:00
|
|
|
sb = next_sync_buff(ipvs, ms);
|
2012-05-08 11:39:49 -06:00
|
|
|
if (unlikely(kthread_should_stop()))
|
|
|
|
break;
|
|
|
|
if (!sb) {
|
|
|
|
schedule_timeout(IPVS_SYNC_CHECK_PERIOD);
|
|
|
|
continue;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2012-05-08 11:39:49 -06:00
|
|
|
while (ip_vs_send_sync_msg(tinfo->sock, sb->mesg) < 0) {
|
2013-11-12 07:34:24 -07:00
|
|
|
/* (Ab)use interruptible sleep to avoid increasing
|
|
|
|
* the load avg.
|
|
|
|
*/
|
|
|
|
__wait_event_interruptible(*sk_sleep(sk),
|
2012-05-08 11:39:49 -06:00
|
|
|
sock_writeable(sk) ||
|
2013-10-02 03:22:33 -06:00
|
|
|
kthread_should_stop());
|
2012-05-08 11:39:49 -06:00
|
|
|
if (unlikely(kthread_should_stop()))
|
|
|
|
goto done;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2012-05-08 11:39:49 -06:00
|
|
|
ip_vs_sync_buff_release(sb);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2012-05-08 11:39:49 -06:00
|
|
|
done:
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
|
|
if (sb)
|
|
|
|
ip_vs_sync_buff_release(sb);
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
/* clean up the sync_buff queue */
|
2012-05-08 11:40:30 -06:00
|
|
|
while ((sb = sb_dequeue(ipvs, ms)))
|
2005-04-16 16:20:36 -06:00
|
|
|
ip_vs_sync_buff_release(sb);
|
2012-05-08 11:39:49 -06:00
|
|
|
__set_current_state(TASK_RUNNING);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/* clean up the current sync_buff */
|
2012-05-08 11:40:30 -06:00
|
|
|
sb = get_curr_sync_buff(ipvs, ms, 0);
|
2011-01-03 06:44:55 -07:00
|
|
|
if (sb)
|
2005-04-16 16:20:36 -06:00
|
|
|
ip_vs_sync_buff_release(sb);
|
|
|
|
|
|
|
|
/* release the sending multicast socket */
|
2015-05-08 20:10:31 -06:00
|
|
|
sock_release(tinfo->sock);
|
2008-07-16 05:13:50 -06:00
|
|
|
kfree(tinfo);
|
|
|
|
|
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
static int sync_thread_backup(void *data)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2008-07-16 05:13:50 -06:00
|
|
|
struct ip_vs_sync_thread_data *tinfo = data;
|
2015-09-21 12:02:14 -06:00
|
|
|
struct netns_ipvs *ipvs = tinfo->ipvs;
|
2005-04-16 16:20:36 -06:00
|
|
|
int len;
|
|
|
|
|
2009-08-02 05:05:41 -06:00
|
|
|
pr_info("sync thread started: state = BACKUP, mcast_ifn = %s, "
|
2012-05-08 11:40:30 -06:00
|
|
|
"syncid = %d, id = %d\n",
|
2015-07-26 06:03:27 -06:00
|
|
|
ipvs->bcfg.mcast_ifn, ipvs->bcfg.syncid, tinfo->id);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
while (!kthread_should_stop()) {
|
2010-04-20 07:03:51 -06:00
|
|
|
wait_event_interruptible(*sk_sleep(tinfo->sock->sk),
|
2008-07-16 05:13:56 -06:00
|
|
|
!skb_queue_empty(&tinfo->sock->sk->sk_receive_queue)
|
|
|
|
|| kthread_should_stop());
|
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
/* do we have data now? */
|
|
|
|
while (!skb_queue_empty(&(tinfo->sock->sk->sk_receive_queue))) {
|
|
|
|
len = ip_vs_receive(tinfo->sock, tinfo->buf,
|
2015-07-26 06:03:27 -06:00
|
|
|
ipvs->bcfg.sync_maxlen);
|
2008-07-16 05:13:50 -06:00
|
|
|
if (len <= 0) {
|
2012-05-08 11:40:30 -06:00
|
|
|
if (len != -EAGAIN)
|
|
|
|
pr_err("receiving message error\n");
|
2005-04-16 16:20:36 -06:00
|
|
|
break;
|
|
|
|
}
|
2008-07-16 05:13:50 -06:00
|
|
|
|
2015-09-21 12:02:15 -06:00
|
|
|
ip_vs_process_message(ipvs, tinfo->buf, len);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* release the sending multicast socket */
|
2015-05-08 20:10:31 -06:00
|
|
|
sock_release(tinfo->sock);
|
2008-07-16 05:13:50 -06:00
|
|
|
kfree(tinfo->buf);
|
|
|
|
kfree(tinfo);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2015-09-21 12:02:10 -06:00
|
|
|
int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
|
2015-07-26 06:03:27 -06:00
|
|
|
int state)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
struct ip_vs_sync_thread_data *tinfo = NULL;
|
2012-05-08 11:40:30 -06:00
|
|
|
struct task_struct **array = NULL, *task;
|
2015-07-26 06:03:27 -06:00
|
|
|
struct net_device *dev;
|
2012-05-08 11:40:30 -06:00
|
|
|
char *name;
|
2008-07-16 05:13:50 -06:00
|
|
|
int (*threadfn)(void *data);
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
int id = 0, count, hlen;
|
2008-07-16 05:13:50 -06:00
|
|
|
int result = -ENOMEM;
|
2015-07-26 06:03:27 -06:00
|
|
|
u16 mtu, min_mtu;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2009-08-02 05:05:41 -06:00
|
|
|
IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
|
2017-02-27 15:30:02 -07:00
|
|
|
IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %zd bytes\n",
|
2010-11-19 06:25:11 -07:00
|
|
|
sizeof(struct ip_vs_sync_conn_v0));
|
2005-04-16 16:20:36 -06:00
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
/* Do not hold one mutex and then to block on another */
|
|
|
|
for (;;) {
|
|
|
|
rtnl_lock();
|
|
|
|
if (mutex_trylock(&ipvs->sync_mutex))
|
|
|
|
break;
|
|
|
|
rtnl_unlock();
|
|
|
|
mutex_lock(&ipvs->sync_mutex);
|
|
|
|
if (rtnl_trylock())
|
|
|
|
break;
|
|
|
|
mutex_unlock(&ipvs->sync_mutex);
|
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!ipvs->sync_state) {
|
|
|
|
count = clamp(sysctl_sync_ports(ipvs), 1, IPVS_SYNC_PORTS_MAX);
|
|
|
|
ipvs->threads_mask = count - 1;
|
|
|
|
} else
|
|
|
|
count = ipvs->threads_mask + 1;
|
2011-10-10 19:54:35 -06:00
|
|
|
|
2015-07-26 06:03:28 -06:00
|
|
|
if (c->mcast_af == AF_UNSPEC) {
|
|
|
|
c->mcast_af = AF_INET;
|
|
|
|
c->mcast_group.ip = cpu_to_be32(IP_VS_SYNC_GROUP);
|
|
|
|
}
|
|
|
|
if (!c->mcast_port)
|
|
|
|
c->mcast_port = IP_VS_SYNC_PORT;
|
|
|
|
if (!c->mcast_ttl)
|
|
|
|
c->mcast_ttl = 1;
|
|
|
|
|
2015-09-21 12:02:10 -06:00
|
|
|
dev = __dev_get_by_name(ipvs->net, c->mcast_ifn);
|
2015-07-26 06:03:27 -06:00
|
|
|
if (!dev) {
|
|
|
|
pr_err("Unknown mcast interface: %s\n", c->mcast_ifn);
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -ENODEV;
|
|
|
|
goto out_early;
|
2015-07-26 06:03:27 -06:00
|
|
|
}
|
2015-07-26 06:03:28 -06:00
|
|
|
hlen = (AF_INET6 == c->mcast_af) ?
|
|
|
|
sizeof(struct ipv6hdr) + sizeof(struct udphdr) :
|
|
|
|
sizeof(struct iphdr) + sizeof(struct udphdr);
|
2015-07-26 06:03:27 -06:00
|
|
|
mtu = (state == IP_VS_STATE_BACKUP) ?
|
|
|
|
clamp(dev->mtu, 1500U, 65535U) : 1500U;
|
|
|
|
min_mtu = (state == IP_VS_STATE_BACKUP) ? 1024 : 1;
|
|
|
|
|
|
|
|
if (c->sync_maxlen)
|
|
|
|
c->sync_maxlen = clamp_t(unsigned int,
|
|
|
|
c->sync_maxlen, min_mtu,
|
|
|
|
65535 - hlen);
|
|
|
|
else
|
|
|
|
c->sync_maxlen = mtu - hlen;
|
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
if (state == IP_VS_STATE_MASTER) {
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -EEXIST;
|
2012-05-08 11:40:30 -06:00
|
|
|
if (ipvs->ms)
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto out_early;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2015-07-26 06:03:27 -06:00
|
|
|
ipvs->mcfg = *c;
|
2012-05-08 11:40:30 -06:00
|
|
|
name = "ipvs-m:%d:%d";
|
2008-07-16 05:13:50 -06:00
|
|
|
threadfn = sync_thread_master;
|
|
|
|
} else if (state == IP_VS_STATE_BACKUP) {
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -EEXIST;
|
2012-05-08 11:40:30 -06:00
|
|
|
if (ipvs->backup_threads)
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto out_early;
|
2008-07-16 05:13:50 -06:00
|
|
|
|
2015-07-26 06:03:27 -06:00
|
|
|
ipvs->bcfg = *c;
|
2012-05-08 11:40:30 -06:00
|
|
|
name = "ipvs-b:%d:%d";
|
2008-07-16 05:13:50 -06:00
|
|
|
threadfn = sync_thread_backup;
|
2005-04-16 16:20:36 -06:00
|
|
|
} else {
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -EINVAL;
|
|
|
|
goto out_early;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
if (state == IP_VS_STATE_MASTER) {
|
|
|
|
struct ipvs_master_sync_state *ms;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -ENOMEM;
|
2017-03-28 04:36:49 -06:00
|
|
|
ipvs->ms = kcalloc(count, sizeof(ipvs->ms[0]), GFP_KERNEL);
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!ipvs->ms)
|
|
|
|
goto out;
|
|
|
|
ms = ipvs->ms;
|
|
|
|
for (id = 0; id < count; id++, ms++) {
|
|
|
|
INIT_LIST_HEAD(&ms->sync_queue);
|
|
|
|
ms->sync_queue_len = 0;
|
|
|
|
ms->sync_queue_delay = 0;
|
|
|
|
INIT_DELAYED_WORK(&ms->master_wakeup_work,
|
|
|
|
master_wakeup_work_handler);
|
|
|
|
ms->ipvs = ipvs;
|
|
|
|
}
|
|
|
|
} else {
|
2017-03-28 04:36:49 -06:00
|
|
|
array = kcalloc(count, sizeof(struct task_struct *),
|
2012-05-08 11:40:30 -06:00
|
|
|
GFP_KERNEL);
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -ENOMEM;
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!array)
|
|
|
|
goto out;
|
2008-07-16 05:13:50 -06:00
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
for (id = 0; id < count; id++) {
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
result = -ENOMEM;
|
2012-05-08 11:40:30 -06:00
|
|
|
tinfo = kmalloc(sizeof(*tinfo), GFP_KERNEL);
|
|
|
|
if (!tinfo)
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto out;
|
2015-09-21 12:02:14 -06:00
|
|
|
tinfo->ipvs = ipvs;
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
tinfo->sock = NULL;
|
2012-05-08 11:40:30 -06:00
|
|
|
if (state == IP_VS_STATE_BACKUP) {
|
2015-07-26 06:03:27 -06:00
|
|
|
tinfo->buf = kmalloc(ipvs->bcfg.sync_maxlen,
|
2012-05-08 11:40:30 -06:00
|
|
|
GFP_KERNEL);
|
|
|
|
if (!tinfo->buf)
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto out;
|
2013-01-25 08:44:57 -07:00
|
|
|
} else {
|
|
|
|
tinfo->buf = NULL;
|
2012-05-08 11:40:30 -06:00
|
|
|
}
|
|
|
|
tinfo->id = id;
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
if (state == IP_VS_STATE_MASTER)
|
|
|
|
result = make_send_sock(ipvs, id, dev, &tinfo->sock);
|
|
|
|
else
|
|
|
|
result = make_receive_sock(ipvs, id, dev, &tinfo->sock);
|
|
|
|
if (result < 0)
|
|
|
|
goto out;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2012-05-08 11:40:30 -06:00
|
|
|
task = kthread_run(threadfn, tinfo, name, ipvs->gen, id);
|
|
|
|
if (IS_ERR(task)) {
|
|
|
|
result = PTR_ERR(task);
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
goto out;
|
2012-05-08 11:40:30 -06:00
|
|
|
}
|
|
|
|
tinfo = NULL;
|
|
|
|
if (state == IP_VS_STATE_MASTER)
|
|
|
|
ipvs->ms[id].master_thread = task;
|
|
|
|
else
|
|
|
|
array[id] = task;
|
2008-07-16 05:13:50 -06:00
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
/* mark as active */
|
2012-05-08 11:40:30 -06:00
|
|
|
|
|
|
|
if (state == IP_VS_STATE_BACKUP)
|
|
|
|
ipvs->backup_threads = array;
|
|
|
|
spin_lock_bh(&ipvs->sync_buff_lock);
|
2011-01-03 06:44:55 -07:00
|
|
|
ipvs->sync_state |= state;
|
2012-05-08 11:40:30 -06:00
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
mutex_unlock(&ipvs->sync_mutex);
|
|
|
|
rtnl_unlock();
|
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
/* increase the module use count */
|
|
|
|
ip_vs_use_count_inc();
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
out:
|
|
|
|
/* We do not need RTNL lock anymore, release it here so that
|
|
|
|
* sock_release below and in the kthreads can use rtnl_lock
|
|
|
|
* to leave the mcast group.
|
|
|
|
*/
|
|
|
|
rtnl_unlock();
|
2012-05-08 11:40:30 -06:00
|
|
|
count = id;
|
|
|
|
while (count-- > 0) {
|
|
|
|
if (state == IP_VS_STATE_MASTER)
|
|
|
|
kthread_stop(ipvs->ms[count].master_thread);
|
|
|
|
else
|
|
|
|
kthread_stop(array[count]);
|
|
|
|
}
|
|
|
|
if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
|
|
|
|
kfree(ipvs->ms);
|
|
|
|
ipvs->ms = NULL;
|
|
|
|
}
|
ipvs: fix rtnl_lock lockups caused by start_sync_thread
syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]
We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:
1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).
2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.
Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.
Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.
[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
(rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(rtnl_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by syzkaller688027/4497:
#0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
check_deadlock kernel/locking/lockdep.c:1805 [inline]
validate_chain kernel/locking/lockdep.c:2401 [inline]
__lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
sock_release+0x8d/0x1e0 net/socket.c:595
start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
SYSC_setsockopt net/socket.c:1849 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1828
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60
[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7 D23688 25421 4408 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
do_wait_for_common kernel/sched/completion.c:86 [inline]
__wait_for_common kernel/sched/completion.c:107 [inline]
wait_for_common kernel/sched/completion.c:118 [inline]
wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
SYSC_setsockopt net/socket.c:1850 [inline]
SyS_setsockopt+0x189/0x360 net/socket.c:1829
do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001
Showing all locks held in the system:
2 locks held by khungtaskd/868:
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
#0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
#0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
#0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
#0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
#1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
#0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-07 06:50:47 -06:00
|
|
|
mutex_unlock(&ipvs->sync_mutex);
|
|
|
|
if (tinfo) {
|
|
|
|
if (tinfo->sock)
|
|
|
|
sock_release(tinfo->sock);
|
|
|
|
kfree(tinfo->buf);
|
|
|
|
kfree(tinfo);
|
|
|
|
}
|
|
|
|
kfree(array);
|
|
|
|
return result;
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|
|
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|
|
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out_early:
|
|
|
|
mutex_unlock(&ipvs->sync_mutex);
|
|
|
|
rtnl_unlock();
|
2008-07-16 05:13:50 -06:00
|
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|
return result;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
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|
|
|
|
|
|
2015-09-21 12:02:11 -06:00
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|
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int stop_sync_thread(struct netns_ipvs *ipvs, int state)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2012-05-08 11:40:30 -06:00
|
|
|
struct task_struct **array;
|
|
|
|
int id;
|
2011-05-03 14:09:30 -06:00
|
|
|
int retc = -EINVAL;
|
2011-01-03 06:44:55 -07:00
|
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|
|
2009-08-02 05:05:41 -06:00
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IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
|
2005-04-16 16:20:36 -06:00
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|
|
|
|
|
|
if (state == IP_VS_STATE_MASTER) {
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!ipvs->ms)
|
2008-07-16 05:13:50 -06:00
|
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|
return -ESRCH;
|
2007-06-18 23:33:20 -06:00
|
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|
|
2008-07-16 05:13:50 -06:00
|
|
|
/*
|
|
|
|
* The lock synchronizes with sb_queue_tail(), so that we don't
|
|
|
|
* add sync buffers to the queue, when we are already in
|
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|
|
* progress of stopping the master sync daemon.
|
|
|
|
*/
|
2005-04-16 16:20:36 -06:00
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|
|
2012-05-08 11:40:30 -06:00
|
|
|
spin_lock_bh(&ipvs->sync_buff_lock);
|
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|
|
spin_lock(&ipvs->sync_lock);
|
2011-01-03 06:44:55 -07:00
|
|
|
ipvs->sync_state &= ~IP_VS_STATE_MASTER;
|
2012-05-08 11:40:30 -06:00
|
|
|
spin_unlock(&ipvs->sync_lock);
|
|
|
|
spin_unlock_bh(&ipvs->sync_buff_lock);
|
|
|
|
|
|
|
|
retc = 0;
|
|
|
|
for (id = ipvs->threads_mask; id >= 0; id--) {
|
|
|
|
struct ipvs_master_sync_state *ms = &ipvs->ms[id];
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
pr_info("stopping master sync thread %d ...\n",
|
|
|
|
task_pid_nr(ms->master_thread));
|
|
|
|
cancel_delayed_work_sync(&ms->master_wakeup_work);
|
|
|
|
ret = kthread_stop(ms->master_thread);
|
|
|
|
if (retc >= 0)
|
|
|
|
retc = ret;
|
|
|
|
}
|
|
|
|
kfree(ipvs->ms);
|
|
|
|
ipvs->ms = NULL;
|
2008-07-16 05:13:50 -06:00
|
|
|
} else if (state == IP_VS_STATE_BACKUP) {
|
2012-05-08 11:40:30 -06:00
|
|
|
if (!ipvs->backup_threads)
|
2008-07-16 05:13:50 -06:00
|
|
|
return -ESRCH;
|
|
|
|
|
2011-01-03 06:44:55 -07:00
|
|
|
ipvs->sync_state &= ~IP_VS_STATE_BACKUP;
|
2012-05-08 11:40:30 -06:00
|
|
|
array = ipvs->backup_threads;
|
|
|
|
retc = 0;
|
|
|
|
for (id = ipvs->threads_mask; id >= 0; id--) {
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
pr_info("stopping backup sync thread %d ...\n",
|
|
|
|
task_pid_nr(array[id]));
|
|
|
|
ret = kthread_stop(array[id]);
|
|
|
|
if (retc >= 0)
|
|
|
|
retc = ret;
|
|
|
|
}
|
|
|
|
kfree(array);
|
|
|
|
ipvs->backup_threads = NULL;
|
2008-07-16 05:13:50 -06:00
|
|
|
}
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2008-07-16 05:13:50 -06:00
|
|
|
/* decrease the module use count */
|
|
|
|
ip_vs_use_count_dec();
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2011-05-03 14:09:30 -06:00
|
|
|
return retc;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2011-01-03 06:44:42 -07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Initialize data struct for each netns
|
|
|
|
*/
|
2015-09-21 12:02:20 -06:00
|
|
|
int __net_init ip_vs_sync_net_init(struct netns_ipvs *ipvs)
|
2011-01-03 06:44:42 -07:00
|
|
|
{
|
2011-10-10 19:54:35 -06:00
|
|
|
__mutex_init(&ipvs->sync_mutex, "ipvs->sync_mutex", &__ipvs_sync_key);
|
2011-01-03 06:44:55 -07:00
|
|
|
spin_lock_init(&ipvs->sync_lock);
|
|
|
|
spin_lock_init(&ipvs->sync_buff_lock);
|
2011-01-03 06:44:42 -07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2015-09-21 12:02:21 -06:00
|
|
|
void ip_vs_sync_net_cleanup(struct netns_ipvs *ipvs)
|
2011-01-03 06:44:42 -07:00
|
|
|
{
|
2011-05-03 14:09:30 -06:00
|
|
|
int retc;
|
|
|
|
|
2011-10-10 19:54:35 -06:00
|
|
|
mutex_lock(&ipvs->sync_mutex);
|
2015-09-21 12:02:11 -06:00
|
|
|
retc = stop_sync_thread(ipvs, IP_VS_STATE_MASTER);
|
2011-05-03 14:09:30 -06:00
|
|
|
if (retc && retc != -ESRCH)
|
|
|
|
pr_err("Failed to stop Master Daemon\n");
|
|
|
|
|
2015-09-21 12:02:11 -06:00
|
|
|
retc = stop_sync_thread(ipvs, IP_VS_STATE_BACKUP);
|
2011-05-03 14:09:30 -06:00
|
|
|
if (retc && retc != -ESRCH)
|
|
|
|
pr_err("Failed to stop Backup Daemon\n");
|
2011-10-10 19:54:35 -06:00
|
|
|
mutex_unlock(&ipvs->sync_mutex);
|
2011-01-03 06:44:42 -07:00
|
|
|
}
|