KCSAN: data-race in __mod_timer / __mod_timer (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0477e928 Linux 5.10-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=109f82f3500000
kernel config: https://syzkaller.appspot.com/x/.config?x=329e76890d0bf5c3
dashboard link: https://syzkaller.appspot.com/bug?extid=31d4e907086795b2dbd4
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [Ja...@zx2c4.com da...@davemloft.net ku...@kernel.org linux-...@vger.kernel.org net...@vger.kernel.org wire...@lists.zx2c4.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+31d4e9...@syzkaller.appspotmail.com

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

write to 0xffff88800c344dc8 of 8 bytes by task 23578 on cpu 1:
__mod_timer+0x9ae/0xbf0 kernel/time/timer.c:1010
mod_timer+0x1b/0x20 kernel/time/timer.c:1106
mod_peer_timer drivers/net/wireguard/timers.c:37 [inline]
wg_timers_any_authenticated_packet_traversal+0xc5/0xf0 drivers/net/wireguard/timers.c:215
wg_packet_create_data_done drivers/net/wireguard/send.c:248 [inline]
wg_packet_tx_worker+0x199/0x4c0 drivers/net/wireguard/send.c:280
process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
worker_thread+0x635/0xb90 kernel/workqueue.c:2418
kthread+0x1fd/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff88800c344dc8 of 8 bytes by task 8112 on cpu 0:
__mod_timer+0x74/0xbf0 kernel/time/timer.c:978
mod_timer+0x1b/0x20 kernel/time/timer.c:1106
mod_peer_timer drivers/net/wireguard/timers.c:37 [inline]
wg_timers_any_authenticated_packet_traversal+0xc5/0xf0 drivers/net/wireguard/timers.c:215
wg_receive_handshake_packet drivers/net/wireguard/receive.c:209 [inline]
wg_packet_handshake_receive_worker+0x3d2/0x440 drivers/net/wireguard/receive.c:220
process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
worker_thread+0x635/0xb90 kernel/workqueue.c:2418
kthread+0x1fd/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: 8112 Comm: kworker/0:3 Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: wg-kex-wg1 wg_packet_handshake_receive_worker
==================================================================


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[syzbot]

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