KCSAN: data-race in exit_signals / kthread

KCSAN: data-race in exit_signals / kthread_stop

Status: auto-closed as invalid on 2021/03/16 14:08
Subsystems: kernel
[Documentation on labels]
First crash: 1181d, last: 1165d

▶ ▼ Similar bugs (1)

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in exit_signals / kthread_stop (2) kernel				1	1110d	1110d	0/26	auto-closed as invalid on 2021/05/17 09:01

Sample crash report:

==================================================================
BUG: KCSAN: data-race in exit_signals / kthread_stop

write to 0xffff888128d1d02c of 4 bytes by task 8363 on cpu 0:
 exit_signals+0x10d/0x540 kernel/signal.c:2865
 do_exit+0x1b4/0x1690 kernel/exit.c:781
 kthread+0x213/0x230 kernel/kthread.c:294
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff888128d1d02c of 4 bytes by task 3171 on cpu 1:
 to_kthread kernel/kthread.c:83 [inline]
 kthread_stop+0x5f/0x2c0 kernel/kthread.c:617
 vhci_shutdown_connection+0x6e/0x680 drivers/usb/usbip/vhci_hcd.c:1019
 event_handler+0x185/0x340 drivers/usb/usbip/usbip_event.c:78
 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:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3171 Comm: kworker/u4:5 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usbip_event event_handler
==================================================================

Crashes (2):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2021/02/09 14:07	upstream	e0756cfc7d7c	2bd9619f	.config	console log	report			info		ci2-upstream-kcsan-gce	KCSAN: data-race in exit_signals / kthread_stop
2021/01/25 05:31	upstream	e68061375f79	52e37319	.config	console log	report			info		ci2-upstream-kcsan-gce	KCSAN: data-race in exit_signals / kthread_stop

* ~~Struck through~~ repros no longer work on HEAD.