KCSAN: data-race in complete_signal / futex_wait_queue

KCSAN: data-race in complete_signal / futex_wait_queue_me (3)
Status: moderation: reported on 2020/07/04 19:02
Reported-by: syzbot+be5052a878945fd5a0a0@syzkaller.appspotmail.com
First crash: 365d, last: 17d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in complete_signal / futex_wait_queue_me				2	586d	590d	0/22	closed as invalid on 2019/11/19 14:54
upstream	KCSAN: data-race in complete_signal / futex_wait_queue_me (2)				18	367d	499d	0/22	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in complete_signal / futex_wait_queue_me

write to 0xffff888100bdf02c of 4 bytes by task 1751 on cpu 0:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule include/linux/freezer.h:171 [inline]
 futex_wait_queue_me+0x198/0x260 kernel/futex.c:2606
 futex_wait+0x143/0x430 kernel/futex.c:2708
 do_futex+0x9d8/0x1ee0 kernel/futex.c:3732
 __do_sys_futex kernel/futex.c:3805 [inline]
 __se_sys_futex+0x21c/0x380 kernel/futex.c:3786
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3786
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100bdf02c of 4 bytes by task 1757 on cpu 1:
 wants_signal kernel/signal.c:1017 [inline]
 complete_signal+0x7c/0x600 kernel/signal.c:1040
 __send_signal+0x680/0x760 kernel/signal.c:1221
 send_signal+0x281/0x390 kernel/signal.c:1284
 do_send_sig_info kernel/signal.c:1333 [inline]
 do_send_specific+0x13d/0x1c0 kernel/signal.c:3881
 do_tkill kernel/signal.c:3907 [inline]
 __do_sys_tgkill kernel/signal.c:3926 [inline]
 __se_sys_tgkill kernel/signal.c:3920 [inline]
 __x64_sys_tgkill+0x108/0x140 kernel/signal.c:3920
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00404040 -> 0x40404040

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1757 Comm: syz-fuzzer Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (373):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/06/02 04:15	upstream	231bc539	032639db	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/28 19:12	upstream	5ff2756a	858ea628	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/25 02:57	upstream	1434a312	3c7fef33	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/23 23:17	upstream	6ebb6814	3c7fef33	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/15 07:43	upstream	25a12987	8bdd5343	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/12 18:13	upstream	dbb5afad	86294427	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/11 20:04	upstream	88b06399	b3c3bb8e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/10 12:37	upstream	6efb943b	ca873091	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/09 21:32	upstream	9819f682	bc5434be	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/07 04:18	upstream	e4866123	06585184	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/06 10:38	upstream	8404c9fb	06c27ff5	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/04 13:50	upstream	5e321ded	06c27ff5	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/03 13:25	upstream	9ccce092	ad61f371	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/05/01 09:48	upstream	9f67672a	77e2b668	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/29 23:49	upstream	8ca5297e	77e2b668	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/28 21:09	upstream	68a32ba1	77e2b668	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/26 23:38	upstream	9f4ad9e4	8ee2dea6	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/26 09:42	upstream	9f4ad9e4	805b5003	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/25 17:36	upstream	d2d09fbe	36c88236	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/25 08:19	upstream	2a1d7946	36c88236	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/23 12:39	upstream	18a3c5f7	17f0b706	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/21 08:33	upstream	1fe5501b	95777977	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/20 08:01	upstream	7af08140	c0ced557	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/19 22:30	upstream	7af08140	4285c989	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/17 20:37	upstream	194cf482	7e2b734b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/16 12:24	upstream	7e25f40e	7e2b734b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/15 16:40	upstream	7f75285c	c59079a6	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/14 23:38	upstream	7f75285c	fcdb12ba	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/14 10:26	upstream	50987bec	3134b37f	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/13 20:20	upstream	89698bec	a184b83e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/12 23:13	upstream	89698bec	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/05 18:28	upstream	0a50438c	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/03 13:56	upstream	d93a0d43	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/02 09:01	upstream	1678e493	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/04/01 18:39	upstream	ffd9fb54	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/31 06:41	upstream	5e46d1b7	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/29 20:14	upstream	1e43c377	6a81331a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/28 20:53	upstream	36a14638	a8529b82	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/26 11:49	upstream	db24726b	a8529b82	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/25 21:56	upstream	00232240	6a383ecf	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/23 16:03	upstream	84196390	e613994b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/22 03:27	upstream	5ee96fa9	bea32f74	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/21 23:25	upstream	5ee96fa9	4c9a64da	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/21 14:33	upstream	812da4d3	4c9a64da	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/16 20:35	upstream	54c6247d	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2020/07/03 12:02	upstream	cdd3bb54	6e569755	.config	log	report
ci2-upstream-kcsan-gce	2020/06/30 18:59	upstream	7c30b859	917afeaa	.config	log	report
ci2-upstream-kcsan-gce	2020/06/19 03:27	upstream	5e857ce6	bc258b50	.config	log	report