[moderation] [fs?] KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (13)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 231825b2e1ff Revert "unicode: Don't special case ignorable..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16440730580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1fe4854f351e948c
dashboard link: https://syzkaller.appspot.com/bug?extid=dc19f2afe4f9b493a78d
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/2b0803efda5c/disk-231825b2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/82759e606254/vmlinux-231825b2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/42a011fdee37/bzImage-231825b2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dc19f2...@syzkaller.appspotmail.com

EXT4-fs (loop2): re-mounted 00000000-0000-0000-0000-000000000000 ro. Quota mode: writeback.
==================================================================
BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu

write to 0xffff888237d2ba28 of 8 bytes by task 24 on cpu 1:
__invalidate_bh_lrus fs/buffer.c:1499 [inline]
invalidate_bh_lrus_cpu+0x85/0xc0 fs/buffer.c:1544
lru_add_and_bh_lrus_drain mm/swap.c:714 [inline]
lru_add_drain_per_cpu+0x62/0x80 mm/swap.c:733
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
kthread+0x1d1/0x210 kernel/kthread.c:389
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 0xffff888237d2ba28 of 8 bytes by task 4812 on cpu 0:
has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1521
smp_call_function_many_cond+0x2d5/0xc20 kernel/smp.c:837
on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1051
on_each_cpu_cond include/linux/smp.h:105 [inline]
invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1530
invalidate_bdev+0x42/0x70 block/bdev.c:100
reconfigure_super+0x439/0x5b0 fs/super.c:1106
do_remount fs/namespace.c:3047 [inline]
path_mount+0x967/0xb30 fs/namespace.c:3826
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount+0x27c/0x2d0 fs/namespace.c:4034
__x64_sys_mount+0x67/0x80 fs/namespace.c:4034
x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff8881007aa138 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4812 Comm: syz.2.323 Not tainted 6.13.0-rc2-syzkaller-00036-g231825b2e1ff #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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[syzbot]

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