[moderation] [block?] KCSAN: data-race in __bio_queue_enter / blk_mq_unfreeze_queue (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1b907d050735 Merge tag '6.7-rc-smb3-client-fixes-part2' of..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=127e4b47680000
kernel config: https://syzkaller.appspot.com/x/.config?x=1c4caf9f31b81308
dashboard link: https://syzkaller.appspot.com/bug?extid=0f779223b8c9e8bd882a
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/b5fc887c0635/disk-1b907d05.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9e7fb6111fb0/vmlinux-1b907d05.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f40a896ae841/bzImage-1b907d05.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0f7792...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __bio_queue_enter / blk_mq_unfreeze_queue

read-write to 0xffff888101980d94 of 4 bytes by task 9714 on cpu 1:
__blk_mq_unfreeze_queue block/blk-mq.c:185 [inline]
blk_mq_unfreeze_queue+0x38/0xc0 block/blk-mq.c:196
loop_set_status+0x414/0x550 drivers/block/loop.c:1312
lo_ioctl+0x892/0x12e0
blkdev_ioctl+0x375/0x460 block/ioctl.c:633
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xcf/0x140 fs/ioctl.c:857
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888101980d94 of 4 bytes by task 18293 on cpu 0:
__bio_queue_enter+0x1e3/0x4f0 block/blk-core.c:358
bio_queue_enter block/blk.h:70 [inline]
blk_mq_get_new_requests block/blk-mq.c:2861 [inline]
blk_mq_submit_bio+0x359/0xd70 block/blk-mq.c:2972
__submit_bio+0x11c/0x350 block/blk-core.c:599
__submit_bio_noacct_mq block/blk-core.c:678 [inline]
submit_bio_noacct_nocheck+0x449/0x5e0 block/blk-core.c:707
submit_bio_noacct+0x71c/0x8c0 block/blk-core.c:801
submit_bio+0xb7/0xc0 block/blk-core.c:834
mpage_bio_submit_read fs/mpage.c:82 [inline]
mpage_readahead+0x28a/0x2d0 fs/mpage.c:384
blkdev_readahead+0x1c/0x20 block/fops.c:425
read_pages+0x9f/0x530 mm/readahead.c:160
page_cache_ra_unbounded+0x2aa/0x2e0 mm/readahead.c:269
do_page_cache_ra mm/readahead.c:299 [inline]
force_page_cache_ra mm/readahead.c:330 [inline]
page_cache_sync_ra+0x24b/0x2a0 mm/readahead.c:691
page_cache_sync_readahead include/linux/pagemap.h:1266 [inline]
filemap_get_pages+0x251/0xf90 mm/filemap.c:2497
filemap_read+0x214/0x680 mm/filemap.c:2593
blkdev_read_iter+0x217/0x2c0 block/fops.c:742
call_read_iter include/linux/fs.h:2014 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x3c0/0x590 fs/read_write.c:470
ksys_read+0xeb/0x1a0 fs/read_write.c:613
__do_sys_read fs/read_write.c:623 [inline]
__se_sys_read fs/read_write.c:621 [inline]
__x64_sys_read+0x42/0x50 fs/read_write.c:621
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18293 Comm: udevd Not tainted 6.6.0-syzkaller-16176-g1b907d050735 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================
I/O error, dev loop3, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2


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[syzbot]

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