[moderation] [fs?] KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (10)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5939d45155bb Merge tag 'trace-v6.9-rc3' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1123402b180000
kernel config: https://syzkaller.appspot.com/x/.config?x=6a1ac6d65bf295c5
dashboard link: https://syzkaller.appspot.com/bug?extid=83984717e9e47eb21ba3
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/de269661ae3f/disk-5939d451.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f5a7a2ebfc8c/vmlinux-5939d451.xz
kernel image: https://storage.googleapis.com/syzbot-assets/33b7271c393c/bzImage-5939d451.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+839847...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu

write to 0xffff888237c2b990 of 8 bytes by task 3753 on cpu 0:
__invalidate_bh_lrus fs/buffer.c:1488 [inline]
invalidate_bh_lrus_cpu+0x85/0xc0 fs/buffer.c:1533
lru_add_and_bh_lrus_drain mm/swap.c:783 [inline]
lru_add_drain_per_cpu+0x62/0x80 mm/swap.c:802
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
worker_thread+0x526/0x730 kernel/workqueue.c:3416
kthread+0x1d1/0x210 kernel/kthread.c:388
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888237c2b990 of 8 bytes by task 19401 on cpu 1:
has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1510
smp_call_function_many_cond+0x2f6/0xc50 kernel/smp.c:808
on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1023
on_each_cpu_cond include/linux/smp.h:105 [inline]
invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1519
kill_bdev block/bdev.c:84 [inline]
blkdev_flush_mapping+0xb8/0x1c0 block/bdev.c:644
blkdev_put_whole block/bdev.c:675 [inline]
bdev_release+0x2f4/0x410 block/bdev.c:1066
blkdev_release+0x15/0x20 block/fops.c:628
__fput+0x2c1/0x660 fs/file_table.c:422
____fput+0x15/0x20 fs/file_table.c:450
task_work_run+0x13a/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff8881088f3820 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19401 Comm: syz-executor.3 Not tainted 6.9.0-rc3-syzkaller-00286-g5939d45155bb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.


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