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: 260d, last: 20h18m

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	481d	486d	0/21	closed as invalid on 2019/11/19 14:54
upstream	KCSAN: data-race in complete_signal / futex_wait_queue_me (2)				18	262d	394d	0/21	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 0xffff888105d8402c of 4 bytes by task 8381 on cpu 1:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule include/linux/freezer.h:171 [inline]
 futex_wait_queue_me+0x186/0x250 kernel/futex.c:2606
 futex_wait+0x145/0x3d0 kernel/futex.c:2708
 do_futex+0x1062/0x1cd0 kernel/futex.c:3735
 __do_sys_futex kernel/futex.c:3798 [inline]
 __se_sys_futex+0x2a8/0x390 kernel/futex.c:3764
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3764
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888105d8402c of 4 bytes by task 8380 on cpu 0:
 wants_signal kernel/signal.c:978 [inline]
 complete_signal+0x7c/0x600 kernel/signal.c:1001
 __send_signal+0x662/0x780 kernel/signal.c:1181
 send_signal+0x398/0x3e0 kernel/signal.c:1242
 do_send_sig_info+0x9b/0xe0 kernel/signal.c:1291
 do_send_specific+0xc7/0x100 kernel/signal.c:3819
 do_tkill kernel/signal.c:3845 [inline]
 __do_sys_tgkill kernel/signal.c:3864 [inline]
 __se_sys_tgkill kernel/signal.c:3858 [inline]
 __x64_sys_tgkill+0x108/0x140 kernel/signal.c:3858
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8380 Comm: syz-fuzzer Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (315):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/03/06 06:46	upstream	a38fd874	e4b4d570	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/05 18:09	upstream	280d542f	4a024a9b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/05 06:53	upstream	280d542f	9d751681	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/04 20:17	upstream	cee407c5	f89ed068	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/03/03 17:03	upstream	f69d02e3	06ed56cd	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/24 06:20	upstream	c03c21ba	fcc6d71b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/23 16:38	upstream	3b9cdafb	fcc6d71b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/23 02:52	upstream	b12b4724	fcc6d71b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/22 13:29	upstream	31caf8b2	c26fb06b	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/21 05:20	upstream	e767b353	3e5ed8b4	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/20 10:31	upstream	f40ddce8	3e5ed8b4	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/19 15:13	upstream	f40ddce8	f689d40a	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/15 01:49	upstream	f40ddce8	98682e5e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/14 11:43	upstream	358fecee	98682e5e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/12 19:04	upstream	dcc0b490	98682e5e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/07 22:06	upstream	b75dba7f	2ce644fc	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/07 09:09	upstream	825b5991	2ce644fc	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/06 14:47	upstream	1e0d27fc	0655e081	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/04 13:24	upstream	61556703	42b90a7c	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/02/01 02:11	upstream	1048ba83	fc9fd31e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/31 12:18	upstream	6642d600	fc9fd31e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/30 09:12	upstream	0e9bcda5	fc9fd31e	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/28 18:46	upstream	76c057c8	7df34f59	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/28 06:21	upstream	76c057c8	eefc07f2	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/27 20:39	upstream	76c057c8	a57db36f	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/27 18:16	upstream	2ab38c17	a57db36f	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/27 07:00	upstream	2ab38c17	a0ebf917	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/26 16:52	upstream	13391c60	55a7d4df	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/26 12:39	upstream	13391c60	52e37319	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/24 19:35	upstream	e6806137	52e37319	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/23 23:32	upstream	e1ae4b0b	52e37319	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/22 20:39	upstream	83d09ad4	52e37319	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/22 04:42	upstream	83d09ad4	d4f4eca5	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/20 22:01	upstream	75439bc4	d4f4eca5	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/20 05:20	upstream	45dfb8a5	63631df1	.config	log	report	info	KCSAN: data-race in complete_signal / futex_wait_queue_me
ci2-upstream-kcsan-gce	2021/01/18 04:20	upstream	19c329f6	fd103621	.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	2021/01/15 17:43	upstream	5ee88057	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/14 22:54	upstream	14662050	468dbb55	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/14 15:29	upstream	65f0d241	468dbb55	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 23:52	upstream	65f0d241	269d24e8	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 20:52	upstream	65f0d241	a945f0a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 11:28	upstream	e609571b	a945f0a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/12 19:02	upstream	e609571b	0cdd6185	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/12 00:42	upstream	a0d54b4f	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/09 23:01	upstream	2ff90100	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/08 21:08	upstream	6279d812	c104d4a3	.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