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: 54d, last: 8h15m

Sample crash report:

==================================================================
BUG: KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init

write to 0xffff888129892948 of 8 bytes by task 31079 on cpu 1:
 blk_mq_rq_ctx_init+0x3e9/0x4f0 block/blk-mq.c:342
 __blk_mq_alloc_request+0x2a5/0x2c0 block/blk-mq.c:396
 blk_mq_submit_bio+0x275/0x1130 block/blk-mq.c:2160
 __submit_bio_noacct_mq block/blk-core.c:1179 [inline]
 submit_bio_noacct+0x772/0x950 block/blk-core.c:1212
 submit_bio+0x200/0x370 block/blk-core.c:1282
 submit_bh_wbc+0x397/0x3d0 fs/buffer.c:3070
 submit_bh fs/buffer.c:3076 [inline]
 write_dirty_buffer+0xd4/0xe0 fs/buffer.c:3144
 fat_sync_bhs+0x52/0x160 fs/fat/misc.c:357
 fat_ent_write+0x85/0xd0 fs/fat/fatent.c:417
 fat_chain_add+0x149/0x400 fs/fat/misc.c:130
 fat_add_cluster fs/fat/inode.c:113 [inline]
 __fat_get_block fs/fat/inode.c:155 [inline]
 fat_get_block+0x429/0x5a0 fs/fat/inode.c:190
 __block_write_begin_int+0x4bf/0xfd0 fs/buffer.c:2011
 __block_write_begin fs/buffer.c:2061 [inline]
 block_write_begin+0x4f/0x190 fs/buffer.c:2120
 cont_write_begin+0x42c/0x610 fs/buffer.c:2469
 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235
 generic_perform_write+0x196/0x390 mm/filemap.c:3397
 __generic_file_write_iter+0x154/0x330 mm/filemap.c:3526
 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3558
 call_write_iter include/linux/fs.h:1872 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x665/0x6f0 fs/read_write.c:578
 ksys_write+0xce/0x180 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write fs/read_write.c:640 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:640
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888129892948 of 8 bytes by task 31120 on cpu 0:
 blk_mq_rq_ctx_init+0x3d7/0x4f0 block/blk-mq.c:342
 __blk_mq_alloc_request+0x2a5/0x2c0 block/blk-mq.c:396
 blk_mq_submit_bio+0x275/0x1130 block/blk-mq.c:2160
 __submit_bio_noacct_mq block/blk-core.c:1179 [inline]
 submit_bio_noacct+0x772/0x950 block/blk-core.c:1212
 submit_bio+0x200/0x370 block/blk-core.c:1282
 submit_bh_wbc+0x397/0x3d0 fs/buffer.c:3070
 submit_bh fs/buffer.c:3076 [inline]
 __sync_dirty_buffer+0xfa/0x1a0 fs/buffer.c:3162
 sync_dirty_buffer+0x16/0x20 fs/buffer.c:3175
 fat_mirror_bhs+0x248/0x320 fs/fat/fatent.c:398
 fat_ent_write+0xbf/0xd0 fs/fat/fatent.c:421
 fat_chain_add+0x149/0x400 fs/fat/misc.c:130
 fat_add_cluster fs/fat/inode.c:113 [inline]
 __fat_get_block fs/fat/inode.c:155 [inline]
 fat_get_block+0x429/0x5a0 fs/fat/inode.c:190
 __block_write_begin_int+0x4bf/0xfd0 fs/buffer.c:2011
 __block_write_begin fs/buffer.c:2061 [inline]
 block_write_begin+0x4f/0x190 fs/buffer.c:2120
 cont_write_begin+0x42c/0x610 fs/buffer.c:2469
 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235
 generic_perform_write+0x196/0x390 mm/filemap.c:3397
 __generic_file_write_iter+0x154/0x330 mm/filemap.c:3526
 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3558
 call_write_iter include/linux/fs.h:1872 [inline]
 do_iter_readv_writev+0x32e/0x3d0 fs/read_write.c:713
 do_iter_write+0x112/0x4b0 fs/read_write.c:1018
 vfs_iter_write+0x4c/0x70 fs/read_write.c:1059
 iter_file_splice_write+0x41a/0x770 fs/splice.c:750
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x95/0x160 fs/splice.c:1016
 splice_direct_to_actor+0x365/0x660 fs/splice.c:971
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31120 Comm: syz-executor.5 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (235):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Maintainers
ci2-upstream-kcsan-gce	2020/08/11 11:27	upstream	00e4db51	5d3ebca9	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/11 00:24	upstream	4bcf69e5	d3694ffb	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/10 23:22	upstream	fc80c51f	d3694ffb	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/10 10:48	upstream	fc80c51f	7adc7b65	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/09 22:22	upstream	9420f1ce	70301872	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/09 13:41	upstream	06a81c1c	70301872	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/08 23:17	upstream	06a81c1c	f721e4a0	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/08 12:05	upstream	449dc8c9	01975a06	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/08 00:16	upstream	30185b69	ff51e522	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/07 12:05	upstream	86cfccb6	28ac5c9e	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/06 23:39	upstream	d6efb3ac	cb436c69	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/06 11:34	upstream	47ec5303	4ca1c0ea	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/05 21:52	upstream	fffe3ae0	0487ea6f	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/05 09:47	upstream	c0842fbc	b7129355	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/04 21:56	upstream	c0842fbc	02034dac	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/04 11:01	upstream	c0842fbc	80a06902	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/04 00:11	upstream	e4cbce4d	96dd3623	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/03 10:58	upstream	bcf87687	96dd3623	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/02 21:39	upstream	142c3326	96dd3623	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/02 07:15	upstream	ac3a0c84	96dd3623	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/01 17:54	upstream	d52daa86	8df85ed9	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/08/01 03:20	upstream	7dc6fd0f	8df85ed9	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/31 11:49	upstream	d8b9faec	8df85ed9	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/30 22:15	upstream	e2c46b57	8df85ed9	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/30 09:47	upstream	83bdc727	b0947553	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/30 08:26	upstream	83bdc727	233283a1	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/29 19:17	upstream	6ba1b005	233283a1	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/29 07:04	upstream	6ba1b005	19a8de55	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/28 19:33	upstream	6ba1b005	cb93dc6a	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/27 06:25	upstream	92ed3019	cb93dc6a	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/26 19:13	upstream	1ada9010	51265195	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/26 08:49	upstream	04300d66	51265195	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/26 01:29	upstream	04300d66	1f7cc1ca	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/25 11:58	upstream	23ee3e4e	1f7cc1ca	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/24 22:24	upstream	68845a55	554af388	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/24 11:16	upstream	f37e99ac	554af388	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/23 21:30	upstream	f37e99ac	70c104a1	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/23 15:43	upstream	d15be546	70c104a1	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/23 02:23	upstream	d15be546	340ea530	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/22 18:48	upstream	8c26c87b	128cd85f	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/22 13:59	upstream	4fa640dc	128cd85f	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/22 02:09	upstream	4fa640dc	21f1765e	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/21 13:50	upstream	4fa640dc	e562dd8a	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/21 00:58	upstream	4fa640dc	8caeeeb7	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/07/01 14:11	upstream	7c30b859	39acb39d	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/06/27 15:47	upstream	1590a2e1	2defc703	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/06/18 14:32	upstream	1b504402	3ea11d3f	.config	log	report	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org