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Nikita Zhandarovich 2e7ef287f0 ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work
idev->mc_ifc_count can be written over without proper locking.

Originally found by syzbot [1], fix this issue by encapsulating calls
to mld_ifc_stop_work() (and mld_gq_stop_work() for good measure) with
mutex_lock() and mutex_unlock() accordingly as these functions
should only be called with mc_lock per their declarations.

[1]
BUG: KCSAN: data-race in ipv6_mc_down / mld_ifc_work

write to 0xffff88813a80c832 of 1 bytes by task 3771 on cpu 0:
 mld_ifc_stop_work net/ipv6/mcast.c:1080 [inline]
 ipv6_mc_down+0x10a/0x280 net/ipv6/mcast.c:2725
 addrconf_ifdown+0xe32/0xf10 net/ipv6/addrconf.c:3949
 addrconf_notify+0x310/0x980
 notifier_call_chain kernel/notifier.c:93 [inline]
 raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461
 __dev_notify_flags+0x205/0x3d0
 dev_change_flags+0xab/0xd0 net/core/dev.c:8685
 do_setlink+0x9f6/0x2430 net/core/rtnetlink.c:2916
 rtnl_group_changelink net/core/rtnetlink.c:3458 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3717 [inline]
 rtnl_newlink+0xbb3/0x1670 net/core/rtnetlink.c:3754
 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6558
 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6576
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x589/0x650 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1910
 ...

write to 0xffff88813a80c832 of 1 bytes by task 22 on cpu 1:
 mld_ifc_work+0x54c/0x7b0 net/ipv6/mcast.c:2653
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700
 worker_thread+0x525/0x730 kernel/workqueue.c:2781
 ...

Fixes: 2d9a93b490 ("mld: convert from timer to delayed work")
Reported-by: syzbot+a9400cabb1d784e49abf@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000994e09060ebcdffb@google.com/
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240117172102.12001-1-n.zhandarovich@fintech.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-18 09:52:30 -08:00
arch Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
block Many singleton patches against the MM code. The patch series which 2024-01-09 11:18:47 -08:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: scomp - fix req->dst buffer overflow 2023-12-29 11:25:56 +08:00
Documentation Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
drivers mlxsw: spectrum_router: Register netdevice notifier before nexthop 2024-01-18 09:48:09 -08:00
fs Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
include net: netdev_queue: netdev_txq_completed_mb(): fix wake condition 2024-01-13 18:26:23 +00:00
init header cleanups for 6.8 2024-01-10 16:43:55 -08:00
io_uring Many singleton patches against the MM code. The patch series which 2024-01-09 11:18:47 -08:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
lib Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
net ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work 2024-01-18 09:52:30 -08:00
rust net: phy: add Rust Asix PHY driver 2023-12-15 09:35:50 +00:00
samples Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
scripts Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
security header cleanups for 6.8 2024-01-10 16:43:55 -08:00
sound linux_kselftest-kunit-6.8-rc1 2024-01-09 17:16:58 -08:00
tools selftests: mlxsw: qos_pfc: Adjust the test to support 8 lanes 2024-01-18 09:48:09 -08:00
usr usr/Kconfig: fix typos of "its" 2023-12-20 15:02:58 -08:00
virt vfs-6.8.misc 2024-01-08 10:26:08 -08:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/ 2023-10-03 20:49:09 +09:00
.mailmap Networking changes for 6.8. 2024-01-11 10:07:29 -08:00
.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 MAINTAINERS: mark ax25 as Orphan 2024-01-11 16:25:04 -08:00
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: eth: mvneta: update entry 2024-01-14 13:12:26 +00:00
Makefile Quite a lot of kexec work this time around. Many singleton patches in 2024-01-09 11:46:20 -08:00
README

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