KCSAN: data-race in futex_wait_queue_me / prepare

KCSAN: data-race in futex_wait_queue_me / prepare_signal (2)
Status: moderation: reported on 2020/06/21 11:47
Reported-by: syzbot+730a2bbd66878efe4a5a@syzkaller.appspotmail.com
First crash: 568d, last: 14d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in futex_wait_queue_me / prepare_signal				3	589d	600d	0/22	closed as invalid on 2019/11/19 13:54

Sample crash report:

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

write to 0xffff888100c2506c of 4 bytes by task 1744 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+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 0xffff888100c2506c of 4 bytes by task 1747 on cpu 0:
 sig_task_ignored kernel/signal.c:93 [inline]
 sig_ignored kernel/signal.c:118 [inline]
 prepare_signal+0x952/0xeb0 kernel/signal.c:1001
 __send_signal+0x64/0x760 kernel/signal.c:1121
 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: 0 PID: 1747 Comm: syz-fuzzer Tainted: G        W         5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (739):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/06/02 21:46	upstream	324c92e5	0740de69	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/31 09:05	upstream	8124c8a6	032639db	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/30 07:39	upstream	b90e90f4	325a8dab	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/27 12:50	upstream	d7c5303f	858ea628	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/26 06:40	upstream	ad9f25d3	93d3a9f6	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/25 16:48	upstream	a050a6d2	93d3a9f6	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/24 13:39	upstream	c4681547	3c7fef33	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/23 08:07	upstream	4d762034	3c7fef33	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/22 18:50	upstream	23d72926	3c7fef33	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/22 03:34	upstream	45af60e7	3c7fef33	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/20 17:32	upstream	f01da525	c560a65d	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/19 17:51	upstream	c3d0e3fd	a343ba6b	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/17 21:59	upstream	d07f6ca9	a343ba6b	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/17 09:13	upstream	d07f6ca9	a2eb125d	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/17 04:48	upstream	d07f6ca9	f54a5c09	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/16 15:15	upstream	63d1cb53	f54a5c09	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/16 01:23	upstream	c12a29ed	f54a5c09	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/15 10:18	upstream	25a12987	93f844de	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/14 03:59	upstream	315d9931	8bdd5343	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/12 19:21	upstream	dbb5afad	ed7d41c5	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/12 06:43	upstream	88b06399	86294427	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/11 21:19	upstream	88b06399	b3c3bb8e	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/10 12:47	upstream	6efb943b	ca873091	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/09 21:52	upstream	9819f682	bc5434be	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/08 23:38	upstream	b7415964	bc5434be	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/08 10:49	upstream	dd860052	bc5434be	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/07 23:07	upstream	1ad77a05	bc5434be	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/07 08:30	upstream	e4866123	f6da8120	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/07 06:00	upstream	e4866123	06585184	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/05 03:15	upstream	d665ea6e	06c27ff5	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/04 14:06	upstream	5e321ded	06c27ff5	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/03 15:04	upstream	9ccce092	ad61f371	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/03 06:47	upstream	9ccce092	77e2b668	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/05/02 11:47	upstream	17ae69ab	77e2b668	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/30 20:06	upstream	65c61de9	77e2b668	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/29 10:24	upstream	d72cd4ad	77e2b668	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/28 22:14	upstream	68a32ba1	77e2b668	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/27 23:34	upstream	e359bce3	805b5003	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/27 11:33	upstream	4a0225c3	805b5003	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/26 23:31	upstream	9f4ad9e4	8ee2dea6	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/26 10:25	upstream	9f4ad9e4	805b5003	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/25 19:24	upstream	d2d09fbe	2a82f1b3	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/25 08:29	upstream	2a1d7946	36c88236	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/24 18:48	upstream	2a1d7946	17f0b706	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/24 02:06	upstream	8db5efb8	17f0b706	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/22 22:44	upstream	90c911ad	33c28d03	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/22 11:45	upstream	16fc44d6	33c28d03	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/21 18:32	upstream	16fc44d6	95777977	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/19 23:16	upstream	7af08140	4285c989	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/04/19 07:18	upstream	bf05bf16	50f523d7	.config	log	report	info	KCSAN: data-race in futex_wait_queue_me / prepare_signal
ci2-upstream-kcsan-gce	2021/01/17 10:43	upstream	0da0a8a0	813be542	.config	log	report	info
ci2-upstream-kcsan-gce	2020/06/20 10:25	upstream	672f9255	c655ec77	.config	log	report
ci2-upstream-kcsan-gce	2020/06/17 11:39	https://github.com/google/ktsan.git kcsan	7c3cd68e	b6c46f43	.config	log	report
ci2-upstream-kcsan-gce	2019/11/27 00:29	https://github.com/google/ktsan.git kcsan	ef798c30	1048481f	.config	log	report