[moderation] [ext4?] KCSAN: data-race in __mark_inode_dirty / move_expired_inodes (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2c22dc1ee3a1 Merge tag 'mailbox-v6.13' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f615c0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=db310a9aeec0c8cb
dashboard link: https://syzkaller.appspot.com/bug?extid=c50aa50aaaf8db7fb66e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [adilger...@dilger.ca linux...@vger.kernel.org linux-...@vger.kernel.org ty...@mit.edu]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0cb07ee98241/disk-2c22dc1e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ba989cf0a9bd/vmlinux-2c22dc1e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b7e2933ec9ca/bzImage-2c22dc1e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c50aa5...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / move_expired_inodes

read-write to 0xffff8881005e77b8 of 4 bytes by task 3726 on cpu 1:
move_expired_inodes+0x17a/0x410 fs/fs-writeback.c:1457
queue_io+0xe1/0x2e0 fs/fs-writeback.c:1509
wb_writeback+0x237/0x640 fs/fs-writeback.c:2152
wb_check_start_all fs/fs-writeback.c:2284 [inline]
wb_do_writeback fs/fs-writeback.c:2310 [inline]
wb_workfn+0x4ea/0x940 fs/fs-writeback.c:2343
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 0xffff8881005e77b8 of 4 bytes by task 3307 on cpu 0:
__mark_inode_dirty+0x198/0x7e0 fs/fs-writeback.c:2537
mark_buffer_dirty+0x149/0x230 fs/buffer.c:1199
__block_commit_write fs/buffer.c:2189 [inline]
block_page_mkwrite+0x29c/0x3f0 fs/buffer.c:2633
ext4_page_mkwrite+0x73d/0xb70 fs/ext4/inode.c:6180
do_page_mkwrite mm/memory.c:3176 [inline]
wp_page_shared mm/memory.c:3577 [inline]
do_wp_page+0xca1/0x2340 mm/memory.c:3727
handle_pte_fault mm/memory.c:5817 [inline]
__handle_mm_fault mm/memory.c:5944 [inline]
handle_mm_fault+0xc63/0x2ac0 mm/memory.c:6112
do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x3b9/0x650 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0x00000020 -> 0x00010022

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3307 Comm: syz-executor Tainted: G W 6.12.0-syzkaller-09435-g2c22dc1ee3a1 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

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