KCSAN: data-race in wg_packet_decrypt_worker / wg_packet_rx_poll

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2cc3c4b3 Merge tag 'io_uring-5.9-2020-08-15' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13bb1491900000
kernel config: https://syzkaller.appspot.com/x/.config?x=ee0e086f5d2c5987
dashboard link: https://syzkaller.appspot.com/bug?extid=a35e14c38686fcb3df17
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
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+a35e14...@syzkaller.appspotmail.com

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

write to 0xffff8880a1054088 of 8 bytes by interrupt on cpu 0:
counter_validate drivers/net/wireguard/receive.c:327 [inline]
wg_packet_rx_poll+0x4bc/0x1300 drivers/net/wireguard/receive.c:469
napi_poll+0x178/0x4f0 net/core/dev.c:6687
net_rx_action+0x1ba/0x530 net/core/dev.c:6757
__do_softirq+0x198/0x360 kernel/softirq.c:298
asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
__run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
do_softirq_own_stack+0x5d/0x80 arch/x86/kernel/irq_64.c:77
do_softirq+0x86/0xb0 kernel/softirq.c:343
__local_bh_enable_ip+0x63/0x70 kernel/softirq.c:195
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
_raw_spin_unlock_bh+0x33/0x40 kernel/locking/spinlock.c:207
spin_unlock_bh include/linux/spinlock.h:399 [inline]
ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
wg_packet_decrypt_worker+0x6e7/0x720 drivers/net/wireguard/receive.c:507
process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
kthread+0x20d/0x230 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff8880a1054088 of 8 bytes by task 48 on cpu 1:
decrypt_packet drivers/net/wireguard/receive.c:258 [inline]
wg_packet_decrypt_worker+0x223/0x720 drivers/net/wireguard/receive.c:509
process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
kthread+0x20d/0x230 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 48 Comm: kworker/1:1 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: wg-crypt-wg2 wg_packet_decrypt_worker
==================================================================


---
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.