KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a349e4c6 Merge tag 'xfs-5.10-fixes-7' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1304bc35500000
kernel config: https://syzkaller.appspot.com/x/.config?x=89a86a84f1254241
dashboard link: https://syzkaller.appspot.com/bug?extid=69b95a9f2df25e89fe0f
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [bri...@lists.linux-foundation.org da...@davemloft.net ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org nik...@nvidia.com ro...@nvidia.com]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+69b95a...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish

read-write to 0xffff888023429148 of 8 bytes by interrupt on cpu 1:
br_handle_frame_finish+0x939/0xa10 net/bridge/br_input.c:146
br_nf_hook_thresh+0x184/0x1c0 net/bridge/br_netfilter_hooks.c:1021
br_nf_pre_routing_finish_ipv6+0x473/0x490 net/bridge/br_netfilter_ipv6.c:187
NF_HOOK include/linux/netfilter.h:301 [inline]
br_nf_pre_routing_ipv6+0x1ed/0x280 net/bridge/br_netfilter_ipv6.c:236
br_nf_pre_routing+0x4c0/0xb20 net/bridge/br_netfilter_hooks.c:505
nf_hook_entry_hookfn include/linux/netfilter.h:136 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:228 [inline]
br_handle_frame+0x403/0xae0 net/bridge/br_input.c:356
__netif_receive_skb_core+0xa5c/0x1dd0 net/core/dev.c:5209
__netif_receive_skb_one_core net/core/dev.c:5313 [inline]
__netif_receive_skb+0x52/0x1b0 net/core/dev.c:5429
process_backlog+0x23f/0x3d0 net/core/dev.c:6319
napi_poll+0x178/0x4c0 net/core/dev.c:6763
net_rx_action+0x17a/0x480 net/core/dev.c:6833
__do_softirq+0x12c/0x2b1 kernel/softirq.c:298
run_ksoftirqd+0x13/0x20 kernel/softirq.c:653
smpboot_thread_fn+0x34f/0x520 kernel/smpboot.c:165
kthread+0x1fa/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read-write to 0xffff888023429148 of 8 bytes by interrupt on cpu 0:
br_handle_frame_finish+0x939/0xa10 net/bridge/br_input.c:146
br_nf_hook_thresh+0x184/0x1c0 net/bridge/br_netfilter_hooks.c:1021
br_nf_pre_routing_finish_ipv6+0x473/0x490 net/bridge/br_netfilter_ipv6.c:187
NF_HOOK include/linux/netfilter.h:301 [inline]
br_nf_pre_routing_ipv6+0x1ed/0x280 net/bridge/br_netfilter_ipv6.c:236
br_nf_pre_routing+0x4c0/0xb20 net/bridge/br_netfilter_hooks.c:505
nf_hook_entry_hookfn include/linux/netfilter.h:136 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:228 [inline]
br_handle_frame+0x403/0xae0 net/bridge/br_input.c:356
__netif_receive_skb_core+0xa5c/0x1dd0 net/core/dev.c:5209
__netif_receive_skb_one_core net/core/dev.c:5313 [inline]
__netif_receive_skb+0x52/0x1b0 net/core/dev.c:5429
process_backlog+0x23f/0x3d0 net/core/dev.c:6319
napi_poll+0x178/0x4c0 net/core/dev.c:6763
net_rx_action+0x17a/0x480 net/core/dev.c:6833
__do_softirq+0x12c/0x2b1 kernel/softirq.c:298
run_ksoftirqd+0x13/0x20 kernel/softirq.c:653
smpboot_thread_fn+0x34f/0x520 kernel/smpboot.c:165
kthread+0x1fa/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.