alistair23-linux/net
Eric Dumazet 6780db244d sctp: do not leak kernel memory to user space
syzbot produced a nice report [1]

Issue here is that a recvmmsg() managed to leak 8 bytes of kernel memory
to user space, because sin_zero (padding field) was not properly cleared.

[1]
BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline]
BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530 net/socket.c:227
CPU: 1 PID: 3586 Comm: syzkaller481044 Not tainted 4.16.0+ #82
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+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176
 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
 copy_to_user include/linux/uaccess.h:184 [inline]
 move_addr_to_user+0x32e/0x530 net/socket.c:227
 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2211
 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313
 SYSC_recvmmsg+0x29b/0x3e0 net/socket.c:2394
 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x4401c9
RSP: 002b:00007ffc56f73098 EFLAGS: 00000217 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401c9
RDX: 0000000000000001 RSI: 0000000020003ac0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000020003bc0 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401af0
R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000

Local variable description: ----addr@___sys_recvmsg
Variable was created at:
 ___sys_recvmsg+0xd5/0x810 net/socket.c:2172
 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313

Bytes 8-15 of 16 are uninitialized

==================================================================
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 3586 Comm: syzkaller481044 Tainted: G    B            4.16.0+ #82
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+0x185/0x1d0 lib/dump_stack.c:53
 panic+0x39d/0x940 kernel/panic.c:183
 kmsan_report+0x238/0x240 mm/kmsan/kmsan.c:1083
 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176
 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
 copy_to_user include/linux/uaccess.h:184 [inline]
 move_addr_to_user+0x32e/0x530 net/socket.c:227
 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2211
 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313
 SYSC_recvmmsg+0x29b/0x3e0 net/socket.c:2394
 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc:	Vlad Yasevich <vyasevich@gmail.com>
Cc:	Neil Horman <nhorman@tuxdriver.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-08 10:31:51 -04:00
..
6lowpan
9p virtio: bugfixes 2018-02-15 14:29:27 -08:00
802 treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
8021q vlan: also check phy_driver ts_info for vlan's real device 2018-04-01 20:53:50 -04:00
appletalk net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
atm net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
ax25 net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
bluetooth Bluetooth: Mark expected switch fall-throughs 2018-04-01 21:43:03 +03:00
bpf bpf: fix null pointer deref in bpf_prog_test_run_xdp 2018-02-01 07:43:56 -08:00
bridge net: bridge: disable bridge MTU auto tuning if it was set manually 2018-03-31 22:19:00 -04:00
caif net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
can net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ceph net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
core net: fix uninit-value in __hw_addr_add_ex() 2018-04-07 22:32:31 -04:00
dcb
dccp dccp: initialize ireq->ir_mark 2018-04-07 22:32:31 -04:00
decnet net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
dns_resolver net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
dsa Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
ethernet
hsr
ieee802154 inet: frags: fix ip6frag_low_thresh boundary 2018-04-04 12:04:59 -04:00
ife
ipv4 soreuseport: initialise timewait reuseport field 2018-04-07 22:32:32 -04:00
ipv6 net/ipv6: Increment OUTxxx counters after netfilter hook 2018-04-05 22:23:43 -04:00
iucv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
kcm net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
key net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
l2tp net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
l3mdev
lapb treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts 2017-11-21 16:35:54 -08:00
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
mac80211 We have a fair number of patches, but many of them are from the 2018-03-29 16:23:26 -04:00
mac802154 net/mac802154: disambiguate mac80215 vs mac802154 trace events 2018-03-28 22:55:18 +02:00
mpls net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ncsi net/ncsi: check for null return from call to nla_nest_start 2018-03-27 10:38:26 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
netlabel net/netlabel: Add list_next_rcu() in rcu_dereference(). 2017-11-18 10:32:41 +09:00
netlink netlink: fix uninit-value in netlink_sendmsg 2018-04-07 22:32:31 -04:00
netrom net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-02-19 18:46:11 -05:00
nsh
openvswitch ovs: Remove rtnl_lock() from ovs_exit_net() 2018-03-29 13:47:54 -04:00
packet net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
phonet net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
psample
qrtr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-06 01:20:46 -05:00
rds net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
rfkill vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
rose net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
rxrpc rxrpc: Fix undefined packet handling 2018-04-04 11:04:08 -04:00
sched net_sched: fix a missing idr_remove() in u32_delete_key() 2018-04-07 12:36:45 -04:00
sctp sctp: do not leak kernel memory to user space 2018-04-08 10:31:51 -04:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
strparser strparser: Fix sign of err codes 2018-03-27 11:00:18 -04:00
sunrpc net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
switchdev
tipc tipc: Fix namespace violation in tipc_sk_fill_sock_diag 2018-04-04 11:54:35 -04:00
tls tls: support for Inline tls record 2018-03-31 23:37:32 -04:00
unix af_unix: remove redundant lockdep class 2018-04-04 11:13:40 -04:00
vmw_vsock net: make getname() functions return length rather than use int* parameter 2018-02-12 14:15:04 -05:00
wimax
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-03-31 23:33:04 -04:00
x25 net: Use octal not symbolic permissions 2018-03-26 12:07:48 -04:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-01 19:49:34 -04:00
compat.c net: socket: add __compat_sys_...msg() helpers; remove in-kernel calls to compat syscalls 2018-04-02 20:15:20 +02:00
Kconfig Staging/IIO patches for 4.16-rc1 2018-02-01 09:51:57 -08:00
Makefile ipx: move Novell IPX protocol support into staging 2017-11-28 13:55:00 +01:00
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-04-03 14:04:18 -07:00
sysctl_net.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00