KCSAN: data-race in __mod_timer / timer_clear

KCSAN: data-race in __mod_timer / timer_clear_idle
Status: auto-closed as invalid on 2020/09/08 21:36
Reported-by: syzbot+645659910ad2e8adc671@syzkaller.appspotmail.com
First crash: 535d, last: 489d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __mod_timer / timer_clear_idle (3)				8	230d	338d	0/22	auto-closed as invalid on 2021/05/25 13:49
upstream	KCSAN: data-race in __mod_timer / timer_clear_idle (2)				1	432d	432d	0/22	auto-closed as invalid on 2020/11/04 00:53

Sample crash report:

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

write to 0xffff88812c01cb24 of 1 bytes by task 0 on cpu 0:
 timer_clear_idle+0x2e/0x40 kernel/time/timer.c:1687
 tick_nohz_idle_retain_tick+0x3e/0x40 kernel/time/tick-sched.c:1012
 cpuidle_idle_call kernel/sched/idle.c:210 [inline]
 do_idle+0x287/0x310 kernel/sched/idle.c:276
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:372
 rest_init+0xd8/0xe0 init/main.c:705
 arch_call_rest_init+0xa/0xb
 start_kernel+0x608/0x6d0 init/main.c:1043
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

read to 0xffff88812c01cb24 of 1 bytes by task 381 on cpu 1:
 forward_timer_base kernel/time/timer.c:900 [inline]
 __mod_timer+0xa5b/0x1020 kernel/time/timer.c:1021
 add_timer+0x38/0x50 kernel/time/timer.c:1148
 __queue_delayed_work+0xea/0x150 kernel/workqueue.c:1649
 queue_delayed_work_on+0x8d/0xe0 kernel/workqueue.c:1674
 queue_delayed_work include/linux/workqueue.h:522 [inline]
 batadv_nc_start_timer net/batman-adv/network-coding.c:79 [inline]
 batadv_nc_worker+0x9f1/0xa00 net/batman-adv/network-coding.c:740
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 381 Comm: kworker/u4:3 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
==================================================================

Crashes (74):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report
ci2-upstream-kcsan-gce	2020/08/04 21:35	upstream	c0842fbc1b18	02034dac	.config	log	report
ci2-upstream-kcsan-gce	2020/08/03 14:35	upstream	bcf876870b95	96dd3623	.config	log	report
ci2-upstream-kcsan-gce	2020/08/02 09:41	upstream	ac3a0c847296	96dd3623	.config	log	report
ci2-upstream-kcsan-gce	2020/08/01 20:58	upstream	d52daa8620c6	8df85ed9	.config	log	report
ci2-upstream-kcsan-gce	2020/07/30 22:20	upstream	e2c46b5762c6	8df85ed9	.config	log	report
ci2-upstream-kcsan-gce	2020/07/30 18:13	upstream	83bdc7275e62	b0947553	.config	log	report
ci2-upstream-kcsan-gce	2020/07/29 21:32	upstream	6ba1b005ffc3	233283a1	.config	log	report
ci2-upstream-kcsan-gce	2020/07/27 21:05	upstream	92ed30191993	cb93dc6a	.config	log	report
ci2-upstream-kcsan-gce	2020/07/26 09:55	upstream	04300d66f0a0	51265195	.config	log	report
ci2-upstream-kcsan-gce	2020/07/26 02:34	upstream	04300d66f0a0	1f7cc1ca	.config	log	report
ci2-upstream-kcsan-gce	2020/07/25 05:59	upstream	68845a55c31b	0a13649c	.config	log	report
ci2-upstream-kcsan-gce	2020/07/24 14:22	upstream	f37e99aca03f	554af388	.config	log	report
ci2-upstream-kcsan-gce	2020/07/23 20:15	upstream	d15be546031c	70c104a1	.config	log	report
ci2-upstream-kcsan-gce	2020/07/23 07:16	upstream	d15be546031c	340ea530	.config	log	report
ci2-upstream-kcsan-gce	2020/07/22 15:46	upstream	4fa640dc5230	128cd85f	.config	log	report
ci2-upstream-kcsan-gce	2020/07/22 03:14	upstream	4fa640dc5230	21f1765e	.config	log	report
ci2-upstream-kcsan-gce	2020/07/21 17:47	upstream	4fa640dc5230	e562dd8a	.config	log	report
ci2-upstream-kcsan-gce	2020/07/21 01:20	upstream	4fa640dc5230	8caeeeb7	.config	log	report
ci2-upstream-kcsan-gce	2020/07/20 13:21	upstream	5714ee50bb43	8caeeeb7	.config	log	report
ci2-upstream-kcsan-gce	2020/07/19 22:13	upstream	92188b41f139	9c812472	.config	log	report
ci2-upstream-kcsan-gce	2020/07/19 08:40	upstream	f932d58abc38	9c812472	.config	log	report
ci2-upstream-kcsan-gce	2020/07/18 20:10	upstream	6cf7ccba29dc	9c812472	.config	log	report
ci2-upstream-kcsan-gce	2020/07/18 06:46	upstream	6a70f89cc58f	9c812472	.config	log	report
ci2-upstream-kcsan-gce	2020/07/16 20:15	upstream	f8456690ba8e	b090c643	.config	log	report
ci2-upstream-kcsan-gce	2020/07/16 01:23	upstream	994e99a96c9b	ada108d0	.config	log	report
ci2-upstream-kcsan-gce	2020/07/14 02:09	upstream	0dc589da873b	ce4c95b3	.config	log	report
ci2-upstream-kcsan-gce	2020/07/13 22:08	upstream	11ba468877bb	ce4c95b3	.config	log	report
ci2-upstream-kcsan-gce	2020/07/13 15:09	upstream	11ba468877bb	f90ec899	.config	log	report
ci2-upstream-kcsan-gce	2020/07/11 12:41	upstream	1df0d8960499	7ba05d2d	.config	log	report
ci2-upstream-kcsan-gce	2020/07/11 02:17	upstream	a581387e415b	18d18b59	.config	log	report
ci2-upstream-kcsan-gce	2020/07/09 08:09	upstream	0bddd227f3dc	bc238812	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 19:25	upstream	63e1968a2c87	9f9845eb	.config	log	report
ci2-upstream-kcsan-gce	2020/07/08 08:51	upstream	dcde237b9b0e	5962a2dc	.config	log	report
ci2-upstream-kcsan-gce	2020/07/07 22:29	upstream	aa27b32b76d0	08fc4ef1	.config	log	report
ci2-upstream-kcsan-gce	2020/07/07 14:46	upstream	bfe91da29bfa	42723355	.config	log	report
ci2-upstream-kcsan-gce	2020/07/06 22:43	upstream	5c82ec00dd00	ef278c73	.config	log	report
ci2-upstream-kcsan-gce	2020/07/05 19:12	upstream	45a5ac7a5cc3	22f87567	.config	log	report
ci2-upstream-kcsan-gce	2020/07/05 12:43	upstream	35e884f89df4	22f87567	.config	log	report
ci2-upstream-kcsan-gce	2020/07/04 13:28	upstream	35e884f89df4	4f739670	.config	log	report
ci2-upstream-kcsan-gce	2020/07/04 02:28	upstream	0c7d7d1fada7	51095195	.config	log	report
ci2-upstream-kcsan-gce	2020/07/03 19:26	upstream	cdd3bb54332f	6e569755	.config	log	report
ci2-upstream-kcsan-gce	2020/07/02 12:04	upstream	cd77006e01b3	f30c14bf	.config	log	report
ci2-upstream-kcsan-gce	2020/07/02 04:06	upstream	cd77006e01b3	bed10395	.config	log	report
ci2-upstream-kcsan-gce	2020/07/02 02:05	upstream	edb543cfe5db	bed10395	.config	log	report
ci2-upstream-kcsan-gce	2020/07/01 21:00	upstream	edb543cfe5db	695ef2dd	.config	log	report
ci2-upstream-kcsan-gce	2020/07/01 05:07	upstream	7c30b859a947	c0383ebe	.config	log	report
ci2-upstream-kcsan-gce	2020/06/30 22:18	upstream	7c30b859a947	c0383ebe	.config	log	report
ci2-upstream-kcsan-gce	2020/06/30 21:17	upstream	7c30b859a947	c0383ebe	.config	log	report
ci2-upstream-kcsan-gce	2020/06/30 00:07	upstream	7c30b859a947	917afeaa	.config	log	report
ci2-upstream-kcsan-gce	2020/06/29 12:09	upstream	9ebcfadb0610	df01f6fc	.config	log	report
ci2-upstream-kcsan-gce	2020/06/29 09:36	upstream	9ebcfadb0610	0375051c	.config	log	report
ci2-upstream-kcsan-gce	2020/06/28 22:49	upstream	91a9a90d040e	a2cdad9d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/27 22:28	upstream	6116dea80dfd	a2cdad9d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/27 20:05	upstream	6116dea80dfd	a2cdad9d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/27 05:17	upstream	1590a2e1c681	ffec44b5	.config	log	report
ci2-upstream-kcsan-gce	2020/06/27 05:14	upstream	1590a2e1c681	ffec44b5	.config	log	report
ci2-upstream-kcsan-gce	2020/06/26 23:40	upstream	1590a2e1c681	ffec44b5	.config	log	report
ci2-upstream-kcsan-gce	2020/06/26 21:37	upstream	1590a2e1c681	349959fb	.config	log	report
ci2-upstream-kcsan-gce	2020/06/26 08:36	upstream	4a21185cda0f	aea82c00	.config	log	report
ci2-upstream-kcsan-gce	2020/06/26 02:54	upstream	4a21185cda0f	aea82c00	.config	log	report
ci2-upstream-kcsan-gce	2020/06/25 23:51	upstream	908f7d12d3ba	aea82c00	.config	log	report
ci2-upstream-kcsan-gce	2020/06/25 12:30	upstream	8be3a53e18e0	c7b4497a	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 21:28	upstream	26e122e97a3d	9d60b18e	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 12:47	upstream	3e08a95294a4	41694dbf	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 11:54	upstream	3e08a95294a4	41694dbf	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 11:50	upstream	3e08a95294a4	41694dbf	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 11:18	upstream	3e08a95294a4	41694dbf	.config	log	report
ci2-upstream-kcsan-gce	2020/06/24 03:55	upstream	3e08a95294a4	bbad15ae	.config	log	report
ci2-upstream-kcsan-gce	2020/06/23 18:21	upstream	3e08a95294a4	6930bbef	.config	log	report
ci2-upstream-kcsan-gce	2020/06/20 00:13	upstream	672f9255a727	123cf502	.config	log	report
ci2-upstream-kcsan-gce	2020/06/19 02:42	upstream	5e857ce6eae7	bc258b50	.config	log	report