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Nikolay Aleksandrov 92c4ee2520 net: bridge: mcast: wait for previous gc cycles when removing port
syzbot hit a use-after-free[1] which is caused because the bridge doesn't
make sure that all previous garbage has been collected when removing a
port. What happens is:
      CPU 1                   CPU 2
 start gc cycle           remove port
                         acquire gc lock first
 wait for lock
                         call br_multicasg_gc() directly
 acquire lock now but    free port
 the port can be freed
 while grp timers still
 running

Make sure all previous gc cycles have finished by using flush_work before
freeing the port.

[1]
  BUG: KASAN: slab-use-after-free in br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861
  Read of size 8 at addr ffff888071d6d000 by task syz.5.1232/9699

  CPU: 1 PID: 9699 Comm: syz.5.1232 Not tainted 6.10.0-rc5-syzkaller-00021-g24ca36a562d6 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
  Call Trace:
   <IRQ>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
   print_address_description mm/kasan/report.c:377 [inline]
   print_report+0xc3/0x620 mm/kasan/report.c:488
   kasan_report+0xd9/0x110 mm/kasan/report.c:601
   br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861
   call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792
   expire_timers kernel/time/timer.c:1843 [inline]
   __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417
   __run_timer_base kernel/time/timer.c:2428 [inline]
   __run_timer_base kernel/time/timer.c:2421 [inline]
   run_timer_base+0x111/0x190 kernel/time/timer.c:2437

Reported-by: syzbot+263426984509be19c9a0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=263426984509be19c9a0
Fixes: e12cec65b5 ("net: bridge: mcast: destroy all entries via gc")
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20240802080730.3206303-1-razor@blackwall.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-05 16:33:56 -07:00
arch ARM updates for v6.11-rc1 2024-07-29 10:33:51 -07:00
block block: fix deadlock between sd_remove & sd_release 2024-07-24 09:51:21 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto crypto: testmgr - generate power-of-2 lengths more often 2024-07-13 11:50:28 +12:00
Documentation Including fixes from wireless, bleutooth, BPF and netfilter. 2024-08-01 09:42:09 -07:00
drivers net: usb: qmi_wwan: fix memory leak for not ip packets 2024-08-05 11:11:31 +01:00
fs for-6.11-rc1-tag 2024-07-30 19:28:36 -07:00
include Including fixes from wireless, bleutooth, BPF and netfilter. 2024-08-01 09:42:09 -07:00
init Rust changes for v6.11 2024-07-27 13:44:54 -07:00
io_uring io_uring/napi: pass ktime to io_napi_adjust_timeout 2024-07-26 08:31:59 -06:00
ipc sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kernel profiling: remove stale percpu flip buffer variables 2024-07-29 16:34:17 -07:00
lib minmax: don't use max() in situations that want a C constant expression 2024-07-28 20:23:27 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm minmax: make generic MIN() and MAX() macros available everywhere 2024-07-28 15:49:18 -07:00
net net: bridge: mcast: wait for previous gc cycles when removing port 2024-08-05 16:33:56 -07:00
rust Rust changes for v6.11 2024-07-27 13:44:54 -07:00
samples Driver core changes for 6.11-rc1 2024-07-25 10:42:22 -07:00
scripts Kbuild fixes for v6.11 2024-07-28 14:02:48 -07:00
security apparmor-pr-2024-07-24 PR 2024-07-25 2024-07-27 13:28:39 -07:00
sound Devicetree fixes for 6.11, part 1 2024-07-27 12:46:16 -07:00
tools selftests: mptcp: join: test both signal & subflow 2024-08-01 18:24:49 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM generic changes for 6.11 2024-07-16 09:51:36 -04:00
.clang-format Docs: Move clang-format from process/ to dev-tools/ 2024-06-26 16:36:00 -06:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: add script and target to generate pacman package 2024-07-22 01:24:22 +09:00
.mailmap MAINTAINERS: mailmap: update James Clark's email address 2024-07-26 14:32:35 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS tracing: Update of MAINTAINERS and CREDITS file 2024-07-18 14:08:42 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: update status of sky2 and skge drivers 2024-08-02 16:03:32 -07:00
Makefile Linux 6.11-rc1 2024-07-28 14:19:55 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.