KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_do_dispatch

KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_do_dispatch_sched (2)
Status: auto-closed as invalid on 2020/11/14 12:11
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 289d, last: 218d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_do_dispatch_sched				2	326d	331d	0/22	auto-closed as invalid on 2020/07/30 00:43
upstream	KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_do_dispatch_sched (3)				26	3d04h	160d	0/22	moderation: reported on 2020/12/07 11:49

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_do_dispatch_sched

write to 0xffff88812b1dcc10 of 8 bytes by task 3634 on cpu 0:
 INIT_LIST_HEAD include/linux/list.h:36 [inline]
 list_splice_init include/linux/list.h:483 [inline]
 __blk_mq_sched_dispatch_requests+0x16a/0x2a0 block/blk-mq-sched.c:304
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:356
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1531
 __blk_mq_delay_run_hw_queue+0x199/0x340 block/blk-mq.c:1608
 blk_mq_run_hw_queue+0x231/0x260 block/blk-mq.c:1661
 blk_mq_run_hw_queues block/blk-mq.c:1679 [inline]
 blk_mq_requeue_work+0x423/0x490 block/blk-mq.c:816
 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:294

read to 0xffff88812b1dcc10 of 8 bytes by task 3258 on cpu 1:
 list_empty_careful include/linux/list.h:319 [inline]
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:153 [inline]
 blk_mq_do_dispatch_sched+0x17c/0x610 block/blk-mq-sched.c:214
 __blk_mq_sched_dispatch_requests+0x1fd/0x2a0 block/blk-mq-sched.c:325
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:356
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1531
 blk_mq_run_work_fn+0x3d/0x50 block/blk-mq.c:1809
 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:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3258 Comm: kworker/1:1H Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kblockd blk_mq_run_work_fn
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info
ci2-upstream-kcsan-gce	2020/10/10 12:11	upstream	6f2f486d	b74c49a6	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/28 08:40	upstream	a1b8638b	6bfdbe89	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/27 01:51	upstream	eeddbe68	5dd8aee8	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/17 11:12	upstream	5925fa68	8247808b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/06 18:57	upstream	dd9fb9bb	abf9ba4f	.config	log	report
ci2-upstream-kcsan-gce	2020/09/04 20:02	upstream	59126901	abf9ba4f	.config	log	report
ci2-upstream-kcsan-gce	2020/08/23 17:41	upstream	c3d8f220	a6d5f3ad	.config	log	report
ci2-upstream-kcsan-gce	2020/07/31 22:38	upstream	d8b9faec	8df85ed9	.config	log	report