[moderation] [wireguard?] KCSAN: data-race in wg_packet_handshake_receive_worker / wg_packet_rx_poll (12)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 192c0159402e Merge tag 'powerpc-7.0-1' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1100ee5a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=65dd1fe567547a72
dashboard link: https://syzkaller.appspot.com/bug?extid=e66eacb9b49734684ec9
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [Ja...@zx2c4.com andrew...@lunn.ch da...@davemloft.net edum...@google.com ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org pab...@redhat.com wire...@lists.zx2c4.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d57854ce2cf5/disk-192c0159.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3572d59f3ab6/vmlinux-192c0159.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b22873d86a7d/bzImage-192c0159.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e66eac...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in wg_packet_handshake_receive_worker / wg_packet_rx_poll

read-write to 0xffff88811bef5090 of 8 bytes by task 1039 on cpu 0:
update_rx_stats drivers/net/wireguard/receive.c:23 [inline]
wg_receive_handshake_packet drivers/net/wireguard/receive.c:198 [inline]
wg_packet_handshake_receive_worker+0x49f/0x5d0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4cd/0x9d0 kernel/workqueue.c:3340
worker_thread+0x6bc/0x8b0 kernel/workqueue.c:3421
kthread+0x22a/0x280 kernel/kthread.c:467
ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read-write to 0xffff88811bef5090 of 8 bytes by task 10767 on cpu 1:
update_rx_stats drivers/net/wireguard/receive.c:23 [inline]
wg_packet_consume_data_done drivers/net/wireguard/receive.c:358 [inline]
wg_packet_rx_poll+0xed7/0x10f0 drivers/net/wireguard/receive.c:474
__napi_poll+0x5f/0x310 net/core/dev.c:7681
napi_threaded_poll_loop+0x1b9/0x630 net/core/dev.c:7800
napi_threaded_poll+0x15f/0x1f0 net/core/dev.c:7851
kthread+0x22a/0x280 kernel/kthread.c:467
ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000000009a8 -> 0x0000000000000a3c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 10767 Comm: napi/wg2-0 Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
==================================================================


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