1
0
Fork 0
Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
 
 
 
 
 
 
Go to file
David Howells 0ff5b1b50d rxrpc: Fix race between incoming ACK parser and retransmitter
[ Upstream commit 2ad6691d98 ]

There's a race between the retransmission code and the received ACK parser.
The problem is that the retransmission loop has to drop the lock under
which it is iterating through the transmission buffer in order to transmit
a packet, but whilst the lock is dropped, the ACK parser can crank the Tx
window round and discard the packets from the buffer.

The retransmission code then updated the annotations for the wrong packet
and a later retransmission thought it had to retransmit a packet that
wasn't there, leading to a NULL pointer dereference.

Fix this by:

 (1) Moving the annotation change to before we drop the lock prior to
     transmission.  This means we can't vary the annotation depending on
     the outcome of the transmission, but that's fine - we'll retransmit
     again later if it failed now.

 (2) Skipping the packet if the skb pointer is NULL.

The following oops was seen:

	BUG: kernel NULL pointer dereference, address: 000000000000002d
	Workqueue: krxrpcd rxrpc_process_call
	RIP: 0010:rxrpc_get_skb+0x14/0x8a
	...
	Call Trace:
	 rxrpc_resend+0x331/0x41e
	 ? get_vtime_delta+0x13/0x20
	 rxrpc_process_call+0x3c0/0x4ac
	 process_one_work+0x18f/0x27f
	 worker_thread+0x1a3/0x247
	 ? create_worker+0x17d/0x17d
	 kthread+0xe6/0xeb
	 ? kthread_delayed_work_timer_fn+0x83/0x83
	 ret_from_fork+0x1f/0x30

Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-09 09:37:50 +02:00
Documentation dt-bindings: display: mediatek: control dpi pins mode to avoid leakage 2020-06-22 09:30:58 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch arm64: dts: imx8mn-ddr4-evk: correct ldo1/ldo2 voltage range 2020-06-30 15:37:10 -04:00
block block: update hctx map when use multiple maps 2020-06-30 15:37:06 -04:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto crypto: algboss - don't wait during notifier callback 2020-06-24 17:50:51 +02:00
drivers usbnet: smsc95xx: Fix use-after-free after removal 2020-07-09 09:37:49 +02:00
fs io_uring: make sure async workqueue is canceled on exit 2020-07-09 09:37:49 +02:00
include net: qed: fix left elements count calculation 2020-06-30 15:36:58 -04:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel sched/debug: Make sd->flags sysctl read-only 2020-07-09 09:37:50 +02:00
lib test_objagg: Fix potential memory leak in error handling 2020-06-30 15:37:04 -04:00
mm mm/slub: fix stack overruns with SLUB_STATS 2020-07-09 09:37:50 +02:00
net rxrpc: Fix race between incoming ACK parser and retransmitter 2020-07-09 09:37:50 +02:00
samples bpf, xdp, samples: Fix null pointer dereference in *_user code 2020-06-30 15:36:55 -04:00
scripts recordmcount: support >64k sections 2020-06-30 15:37:05 -04:00
security selinux: fix double free 2020-06-24 17:50:48 +02:00
sound ALSA: hda/realtek: Add mute LED and micmute LED support for HP systems 2020-06-30 15:37:06 -04:00
tools selftests/net: report etf errors correctly 2020-06-30 15:36:58 -04:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: Save the host's PtrAuth keys in non-preemptible context 2020-06-17 16:40:38 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 17:22:19 +01:00
Makefile Linux 5.4.50 2020-06-30 16:21:55 -04:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.