[moderation] [block?] KCSAN: data-race in __blk_mq_requeue_request / bt_tags_for_each (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5c24e4e9e708 Merge tag 'hid-for-linus-2024020101' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=158b6588180000
kernel config: https://syzkaller.appspot.com/x/.config?x=4aab723d3dfffc44
dashboard link: https://syzkaller.appspot.com/bug?extid=b0c991a6dcf9c3718ec5
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ax...@kernel.dk linux...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/939a791831ca/disk-5c24e4e9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0ffa996f3841/vmlinux-5c24e4e9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/00a87458e25f/bzImage-5c24e4e9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b0c991...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __blk_mq_requeue_request / bt_tags_for_each

write to 0xffff888102cced60 of 4 bytes by task 77 on cpu 1:
__blk_mq_put_driver_tag block/blk-mq.h:339 [inline]
blk_mq_put_driver_tag block/blk-mq.h:347 [inline]
__blk_mq_requeue_request+0x130/0x2a0 block/blk-mq.c:1438
blk_mq_handle_dev_resource block/blk-mq.c:1939 [inline]
blk_mq_dispatch_rq_list+0x860/0x10a0 block/blk-mq.c:2080
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
__blk_mq_sched_dispatch_requests+0x5ec/0xd20 block/blk-mq-sched.c:309
blk_mq_sched_dispatch_requests+0x78/0xe0 block/blk-mq-sched.c:331
blk_mq_run_work_fn+0x65/0xe0 block/blk-mq.c:2456
process_one_work kernel/workqueue.c:2633 [inline]
process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706
worker_thread+0x525/0x730 kernel/workqueue.c:2787
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffff888102cced60 of 4 bytes by task 27166 on cpu 0:
blk_mq_find_and_get_req block/blk-mq-tag.c:260 [inline]
bt_tags_iter block/blk-mq-tag.c:356 [inline]
__sbitmap_for_each_set include/linux/sbitmap.h:281 [inline]
sbitmap_for_each_set include/linux/sbitmap.h:302 [inline]
bt_tags_for_each+0x2e2/0x500 block/blk-mq-tag.c:391
__blk_mq_all_tag_iter block/blk-mq-tag.c:402 [inline]
blk_mq_tagset_busy_iter+0x114/0x150 block/blk-mq-tag.c:446
scsi_host_busy+0x4f/0x80 drivers/scsi/hosts.c:604
scsi_host_queue_ready drivers/scsi/scsi_lib.c:1341 [inline]
scsi_queue_rq+0x2f3/0x1a00 drivers/scsi/scsi_lib.c:1735
blk_mq_dispatch_rq_list+0x2d9/0x10a0 block/blk-mq.c:2071
__blk_mq_sched_dispatch_requests+0x1ce/0xd20 block/blk-mq-sched.c:301
blk_mq_sched_dispatch_requests+0x78/0xe0 block/blk-mq-sched.c:331
blk_mq_run_hw_queue+0x298/0x4c0 block/blk-mq.c:2286
blk_mq_get_tag+0x479/0x590 block/blk-mq-tag.c:170
__blk_mq_alloc_requests+0x63c/0xa40 block/blk-mq.c:501
blk_mq_get_new_requests block/blk-mq.c:2906 [inline]
blk_mq_submit_bio+0x5ab/0x1020 block/blk-mq.c:3011
__submit_bio+0x11c/0x350 block/blk-core.c:607
__submit_bio_noacct_mq block/blk-core.c:686 [inline]
submit_bio_noacct_nocheck+0x4ad/0x5e0 block/blk-core.c:715
submit_bio_noacct+0x67d/0x830 block/blk-core.c:825
submit_bio+0xb7/0xc0 block/blk-core.c:858
ext4_io_submit fs/ext4/page-io.c:378 [inline]
io_submit_add_bh fs/ext4/page-io.c:419 [inline]
ext4_bio_write_folio+0x6c0/0x9a0 fs/ext4/page-io.c:563
mpage_submit_folio fs/ext4/inode.c:1875 [inline]
mpage_map_and_submit_buffers fs/ext4/inode.c:2121 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2260 [inline]
ext4_do_writepages+0x139f/0x2100 fs/ext4/inode.c:2685
ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2774
do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:388
__filemap_fdatawrite_range mm/filemap.c:421 [inline]
__filemap_fdatawrite mm/filemap.c:427 [inline]
filemap_flush+0x95/0xc0 mm/filemap.c:454
ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3078
ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:169
__fput+0x299/0x630 fs/file_table.c:376
____fput+0x15/0x20 fs/file_table.c:404
task_work_run+0x135/0x1a0 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x604/0x16d0 kernel/exit.c:871
do_group_exit+0x101/0x150 kernel/exit.c:1020
get_signal+0xf4e/0x10a0 kernel/signal.c:2893
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
irqentry_exit_to_user_mode+0x9c/0x130 kernel/entry/common.c:225
irqentry_exit+0x12/0x40 kernel/entry/common.c:328
exc_general_protection+0x33b/0x4c0 arch/x86/kernel/traps.c:643
asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:564

value changed: 0x0000120d -> 0x0000121e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27166 Comm: syz-executor.0 Not tainted 6.8.0-rc2-syzkaller-00084-g5c24e4e9e708 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.