KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx

KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
Status: moderation: reported on 2020/07/01 15:52
Reported-by: syzbot+49a9bcf457723ecaf1cf@syzkaller.appspotmail.com
First crash: 366d, last: 3h02m

Sample crash report:

loop5: detected capacity change from 0 to 270
==================================================================
BUG: KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init

write to 0xffff888100399150 of 8 bytes by task 11800 on cpu 0:
 blk_mq_rq_ctx_init+0x3dc/0x4e0 block/blk-mq.c:344
 __blk_mq_alloc_request+0x270/0x290 block/blk-mq.c:399
 blk_mq_submit_bio+0x26d/0xe90 block/blk-mq.c:2206
 __submit_bio_noacct_mq block/blk-core.c:1014 [inline]
 submit_bio_noacct+0x6f2/0x7e0 block/blk-core.c:1047
 submit_bio+0x16d/0x2b0 block/blk-core.c:1090
 submit_bh_wbc+0x2f3/0x330 fs/buffer.c:3075
 submit_bh fs/buffer.c:3081 [inline]
 block_read_full_page+0x78c/0x870 fs/buffer.c:2360
 blkdev_readpage+0x18/0x20 fs/block_dev.c:644
 filemap_read_page+0x69/0x200 mm/filemap.c:2326
 filemap_update_page mm/filemap.c:2394 [inline]
 filemap_get_pages mm/filemap.c:2490 [inline]
 filemap_read+0xc62/0x1230 mm/filemap.c:2550
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
 blkdev_read_iter+0xb9/0xf0 fs/block_dev.c:1730
 call_read_iter include/linux/fs.h:2108 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x565/0x5d0 fs/read_write.c:496
 ksys_read+0xce/0x180 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:642
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100399150 of 8 bytes by task 11802 on cpu 1:
 blk_mq_rq_ctx_init+0x3ca/0x4e0 block/blk-mq.c:344
 __blk_mq_alloc_request+0x270/0x290 block/blk-mq.c:399
 blk_mq_submit_bio+0x26d/0xe90 block/blk-mq.c:2206
 __submit_bio_noacct_mq block/blk-core.c:1014 [inline]
 submit_bio_noacct+0x6f2/0x7e0 block/blk-core.c:1047
 submit_bio+0x16d/0x2b0 block/blk-core.c:1090
 submit_bh_wbc+0x2f3/0x330 fs/buffer.c:3075
 submit_bh fs/buffer.c:3081 [inline]
 write_dirty_buffer+0xde/0xf0 fs/buffer.c:3149
 fat_sync_bhs+0x52/0x160 fs/fat/misc.c:358
 fat_zeroed_cluster+0x2b3/0x5e0 fs/fat/dir.c:1108
 fat_alloc_new_dir+0x444/0x4b0 fs/fat/dir.c:1185
 vfat_mkdir+0x70/0x210 fs/fat/namei_vfat.c:861
 vfs_mkdir+0x2a4/0x370 fs/namei.c:3813
 do_mkdirat+0x11d/0x200 fs/namei.c:3838
 __do_sys_mkdirat fs/namei.c:3851 [inline]
 __se_sys_mkdirat fs/namei.c:3849 [inline]
 __x64_sys_mkdirat+0x3e/0x50 fs/namei.c:3849
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000000025f -> 0x0000000000000260

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11802 Comm: syz-executor.5 Not tainted 5.13.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1167):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/06/19 22:30	upstream	913ec3c2	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/19 09:19	upstream	9ed13a17	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/18 19:51	upstream	b1edae0d	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/18 00:53	upstream	fd0aa1a4	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/17 11:32	upstream	70585216	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/17 11:29	upstream	70585216	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/16 22:33	upstream	6b00bc63	aba2b2fb	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/16 17:31	upstream	6b00bc63	c06f97ad	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/16 12:10	upstream	94f0b2d4	c06f97ad	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/15 23:14	upstream	94f0b2d4	990d3cbe	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/15 18:32	upstream	94f0b2d4	8022d7e3	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/15 09:25	upstream	009c9aa5	8022d7e3	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/14 09:47	upstream	009c9aa5	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/13 20:37	upstream	e4e45343	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/13 02:09	upstream	8ecfa36c	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/12 11:44	upstream	ad347abe	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/11 22:35	upstream	f21b807c	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/11 10:25	upstream	06af8679	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/10 19:53	upstream	f09eacca	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/10 04:39	upstream	cd1245d7	1ba81399	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/09 12:56	upstream	368094df	84fe5d96	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/09 06:56	upstream	368094df	5c2fe346	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/08 17:36	upstream	4c8684fe	5c2fe346	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/08 08:06	upstream	614124be	5c2fe346	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/07 19:06	upstream	614124be	b718257f	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/07 07:40	upstream	614124be	e59537be	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/06 20:43	upstream	decad3e1	500c2339	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/06 00:08	upstream	f5b6eb1e	500c2339	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/05 10:58	upstream	9d32fa5d	500c2339	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/04 21:48	upstream	16f0596f	500c2339	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/04 18:23	upstream	16f0596f	966a236b	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/04 09:23	upstream	f88cd3fb	966a236b	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/03 19:36	upstream	f88cd3fb	0740de69	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/02 20:40	upstream	324c92e5	0740de69	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/06/02 06:54	upstream	231bc539	032639db	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/31 17:20	upstream	c2131f7e	032639db	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/31 09:10	upstream	8124c8a6	032639db	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/31 00:14	upstream	8124c8a6	325a8dab	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/30 07:44	upstream	b90e90f4	325a8dab	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/29 17:44	upstream	f956cb99	325a8dab	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/29 15:50	upstream	6799d4f2	325a8dab	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/29 09:13	upstream	6799d4f2	858ea628	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/28 19:43	upstream	5ff2756a	858ea628	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/28 01:28	upstream	97e5bf60	858ea628	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/27 12:23	upstream	d7c5303f	858ea628	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/05/26 22:43	upstream	7ac3a1c1	858ea628	.config	log	report	info	KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init
ci2-upstream-kcsan-gce	2021/01/17 10:18	upstream	0da0a8a0	813be542	.config	log	report	info
ci2-upstream-kcsan-gce	2020/07/01 14:11	upstream	7c30b859	39acb39d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/27 15:47	upstream	1590a2e1	2defc703	.config	log	report
ci2-upstream-kcsan-gce	2020/06/18 14:32	upstream	1b504402	3ea11d3f	.config	log	report