KCSAN: data-race in __mod_timer / __mod

KCSAN: data-race in __mod_timer / __mod_timer
Status: auto-closed as invalid on 2020/08/03 09:45
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 475d, last: 475d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __mod_timer / __mod_timer (2)	6	314d	313d	0/22	auto-closed as invalid on 2021/01/11 09:46
upstream	KCSAN: data-race in __mod_timer / __mod_timer (3)	1	275d	275d	0/22	auto-closed as invalid on 2021/02/18 17:11
upstream	KCSAN: data-race in __mod_timer / __mod_timer (4)	1	237d	237d	0/22	auto-closed as invalid on 2021/03/28 20:33
upstream	KCSAN: data-race in __mod_timer / __mod_timer (5)	2	188d	197d	0/22	auto-closed as invalid on 2021/05/17 11:47

Sample crash report:

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

write to 0xffff888100665dc8 of 8 bytes by task 11455 on cpu 0:
 __mod_timer+0x9db/0xf00 kernel/time/timer.c:1001
 mod_timer+0x1b/0x20 kernel/time/timer.c:1100
 mod_peer_timer drivers/net/wireguard/timers.c:37 [inline]
 wg_timers_any_authenticated_packet_traversal+0xc4/0xf0 drivers/net/wireguard/timers.c:215
 wg_packet_create_data_done drivers/net/wireguard/send.c:248 [inline]
 wg_packet_tx_worker+0x1a0/0x4c0 drivers/net/wireguard/send.c:280
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

read to 0xffff888100665dc8 of 8 bytes by task 17 on cpu 1:
 __mod_timer+0x66/0xf00 kernel/time/timer.c:969
 mod_timer+0x1b/0x20 kernel/time/timer.c:1100
 mod_peer_timer drivers/net/wireguard/timers.c:37 [inline]
 wg_timers_any_authenticated_packet_traversal+0xc4/0xf0 drivers/net/wireguard/timers.c:215
 wg_receive_handshake_packet drivers/net/wireguard/receive.c:209 [inline]
 wg_packet_handshake_receive_worker+0x42f/0x480 drivers/net/wireguard/receive.c:220
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.8.0-rc3-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 (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2020/06/29 09:39	upstream	9ebcfadb0610	0375051c	.config	log	report