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: 124d, last: 8h44m

Sample crash report:

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

read-write to 0xffff888101343948 of 8 bytes by task 17251 on cpu 1:
 blk_mq_rq_ctx_init+0x3f0/0x4f0 block/blk-mq.c:342
 __blk_mq_alloc_request+0x295/0x2b0 block/blk-mq.c:396
 blk_mq_submit_bio+0x263/0x1020 block/blk-mq.c:2177
 __submit_bio_noacct_mq block/blk-core.c:1022 [inline]
 submit_bio_noacct+0x77d/0x930 block/blk-core.c:1055
 submit_bio+0x1f3/0x360 block/blk-core.c:1125
 submit_bh_wbc+0x38c/0x3d0 fs/buffer.c:3054
 submit_bh fs/buffer.c:3060 [inline]
 write_dirty_buffer+0xd4/0xe0 fs/buffer.c:3128
 fsync_buffers_list fs/buffer.c:730 [inline]
 sync_mapping_buffers+0x29e/0x7d0 fs/buffer.c:548
 ext4_sync_parent fs/ext4/fsync.c:70 [inline]
 ext4_fsync_nojournal fs/ext4/fsync.c:97 [inline]
 ext4_sync_file+0x4b2/0x690 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2725 [inline]
 ext4_buffered_write_iter+0x363/0x3b0 fs/ext4/file.c:276
 ext4_file_write_iter+0x480/0x10b0 fs/ext4/file.c:501
 call_write_iter include/linux/fs.h:1887 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x630/0x6b0 fs/read_write.c:586
 ksys_write+0xce/0x180 fs/read_write.c:639
 __do_sys_write fs/read_write.c:651 [inline]
 __se_sys_write fs/read_write.c:648 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:648
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read-write to 0xffff888101343948 of 8 bytes by task 17250 on cpu 0:
 blk_mq_rq_ctx_init+0x3f0/0x4f0 block/blk-mq.c:342
 __blk_mq_alloc_request+0x295/0x2b0 block/blk-mq.c:396
 blk_mq_submit_bio+0x263/0x1020 block/blk-mq.c:2177
 __submit_bio_noacct_mq block/blk-core.c:1022 [inline]
 submit_bio_noacct+0x77d/0x930 block/blk-core.c:1055
 submit_bio+0x1f3/0x360 block/blk-core.c:1125
 submit_bh_wbc+0x38c/0x3d0 fs/buffer.c:3054
 submit_bh fs/buffer.c:3060 [inline]
 write_dirty_buffer+0xd4/0xe0 fs/buffer.c:3128
 fsync_buffers_list fs/buffer.c:730 [inline]
 sync_mapping_buffers+0x29e/0x7d0 fs/buffer.c:548
 ext4_sync_parent fs/ext4/fsync.c:70 [inline]
 ext4_fsync_nojournal fs/ext4/fsync.c:97 [inline]
 ext4_sync_file+0x4b2/0x690 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2725 [inline]
 ext4_buffered_write_iter+0x363/0x3b0 fs/ext4/file.c:276
 ext4_file_write_iter+0x480/0x10b0 fs/ext4/file.c:501
 call_write_iter include/linux/fs.h:1887 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x630/0x6b0 fs/read_write.c:586
 ksys_write+0xce/0x180 fs/read_write.c:639
 __do_sys_write fs/read_write.c:651 [inline]
 __se_sys_write fs/read_write.c:648 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:648
 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: 17250 Comm: syz-executor.1 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (527):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci2-upstream-kcsan-gce	2020/10/20 12:32	upstream	270315b8	ff4a3345	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/19 23:01	upstream	bbe85027	ff4a3345	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/19 08:41	upstream	7cf726a5	ff4a3345	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/19 07:06	upstream	7cf726a5	fea47c01	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/18 18:07	upstream	9453b2d4	fea47c01	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/18 01:58	upstream	9d9af100	fea47c01	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/17 12:30	upstream	071a0578	fea47c01	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/16 23:02	upstream	54a4c789	6e262c73	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/16 10:13	upstream	9ff9b0d3	6e262c73	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/15 20:22	upstream	726eb70e	6e262c73	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/15 17:45	upstream	726eb70e	63869021	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/15 08:06	upstream	3e4fb434	63869021	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/15 00:04	upstream	3e4fb434	fc7735a2	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/14 10:38	upstream	b5fc7a89	fc7735a2	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/13 21:18	upstream	6ad4bf6e	fc7735a2	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/13 08:35	upstream	865c50e1	bd69ee0d	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/12 19:12	upstream	1e6d1d96	d32b0bbf	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/12 15:59	upstream	bbf5c979	d32b0bbf	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/12 08:11	upstream	bbf5c979	4a77ae0b	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/11 18:57	upstream	3dd0130f	4a77ae0b	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/11 00:12	upstream	da690031	4a77ae0b	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/10 21:14	upstream	6f2f486d	4a77ae0b	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/10 10:01	upstream	6f2f486d	b74c49a6	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/09 21:39	upstream	8a5f78d9	93817d89	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/09 09:23	upstream	583090b1	fa79ed2a	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/08 20:02	upstream	3d006ee4	92390980	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/08 10:49	upstream	c85fb28b	92390980	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/06 20:01	upstream	c85fb28b	1880b4a9	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/05 20:56	upstream	7575fdda	1880b4a9	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/05 13:28	upstream	549738f1	1880b4a9	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/05 00:13	upstream	549738f1	5ef9c291	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/04 09:14	upstream	22fbc037	5ef9c291	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/03 20:39	upstream	22fbc037	1a3f9408	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/03 16:12	upstream	d3d45f82	1a3f9408	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/03 04:03	upstream	d3d45f82	2653fa43	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/02 12:34	upstream	472e5b05	9602ddf4	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/01 20:40	upstream	fcadab74	9602ddf4	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/01 20:13	upstream	fcadab74	4103fce0	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/10/01 08:56	upstream	60e72093	4103fce0	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/30 22:51	upstream	60e72093	a9767fb2	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/30 18:53	upstream	02de58b2	a9767fb2	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/30 06:44	upstream	02de58b2	8516f6d3	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/30 05:22	upstream	02de58b2	5abc3f1a	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/29 14:24	upstream	fb0155a0	5abc3f1a	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/28 23:19	upstream	fb0155a0	1b88c6d5	.config	log	report	info	axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
ci2-upstream-kcsan-gce	2020/09/28 08:16	upstream	a1b8638b	6bfdbe89	.config	log	report	info	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