KCSAN: data-race in __mod_timer / __mod

KCSAN: data-race in __mod_timer / __mod_timer (5)
Status: auto-closed as invalid on 2021/05/17 11:47
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 112d, last: 102d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __mod_timer / __mod_timer	1	389d	389d	0/22	auto-closed as invalid on 2020/08/03 09:45
upstream	KCSAN: data-race in __mod_timer / __mod_timer (2)	6	228d	228d	0/22	auto-closed as invalid on 2021/01/11 09:46
upstream	KCSAN: data-race in __mod_timer / __mod_timer (3)	1	189d	189d	0/22	auto-closed as invalid on 2021/02/18 17:11
upstream	KCSAN: data-race in __mod_timer / __mod_timer (4)	1	151d	151d	0/22	auto-closed as invalid on 2021/03/28 20:33

Sample crash report:

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

write to 0xffff88813a67dc10 of 8 bytes by task 521 on cpu 1:
 __mod_timer+0x9cd/0xc10 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:247 [inline]
 wg_packet_tx_worker+0xf7/0x360 drivers/net/wireguard/send.c:276
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff88813a67dc10 of 8 bytes by task 9279 on cpu 0:
 __mod_timer+0x74/0xc10 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+0x401/0x450 drivers/net/wireguard/receive.c:220
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9279 Comm: kworker/0:5 Tainted: G        W         5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/04/11 21:47	upstream	7d900724913c	6a81331a	.config	log	report			info	KCSAN: data-race in __mod_timer / __mod_timer
ci2-upstream-kcsan-gce	2021/04/02 10:51	upstream	1678e493d530	6a81331a	.config	log	report			info	KCSAN: data-race in __mod_timer / __mod_timer