[moderation] [ext4?] KCSAN: data-race in __mark_inode_dirty / redirty_tail_locked (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 30f09200cc4a Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13de04b4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=655255e3ef31c19b
dashboard link: https://syzkaller.appspot.com/bug?extid=830d890d69ea579ba0e8
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
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/445be400b5e4/disk-30f09200.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8be295d83690/vmlinux-30f09200.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae2ac2a81686/bzImage-30f09200.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+830d89...@syzkaller.appspotmail.com

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

read-write to 0xffff888106e58a50 of 4 bytes by task 4738 on cpu 1:
redirty_tail_locked+0x56/0x280 fs/fs-writeback.c:1412
requeue_inode fs/fs-writeback.c:-1 [inline]
writeback_sb_inodes+0x72c/0xa30 fs/fs-writeback.c:2044
wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2195
wb_do_writeback fs/fs-writeback.c:2342 [inline]
wb_workfn+0x194/0x910 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
worker_thread+0x582/0x770 kernel/workqueue.c:3427
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888106e58a50 of 4 bytes by task 3304 on cpu 0:
__mark_inode_dirty+0x191/0x750 fs/fs-writeback.c:2588
mark_buffer_dirty+0x133/0x210 fs/buffer.c:1209
block_commit_write fs/buffer.c:2218 [inline]
block_page_mkwrite+0x287/0x3d0 fs/buffer.c:2643
ext4_page_mkwrite+0x859/0xb90 fs/ext4/inode.c:6704
do_page_mkwrite mm/memory.c:3489 [inline]
wp_page_shared mm/memory.c:3890 [inline]
do_wp_page+0xa77/0x2510 mm/memory.c:4109
handle_pte_fault mm/memory.c:6211 [inline]
__handle_mm_fault mm/memory.c:6336 [inline]
handle_mm_fault+0x77d/0x2be0 mm/memory.c:6505
do_user_addr_fault+0x630/0x1080 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

value changed: 0x00020042 -> 0x00000040

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3304 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================


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