[moderation] [ext4?] KCSAN: data-race in __mark_inode_dirty / move_expired_inodes (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4d939780b705 Merge tag 'mm-hotfixes-stable-2024-10-17-16-0..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12704c5f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=fd83253b74c9c570
dashboard link: https://syzkaller.appspot.com/bug?extid=85bae17702fc7d1b6960
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/23339caf5f39/disk-4d939780.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eb07ff299133/vmlinux-4d939780.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6f92d56b742d/bzImage-4d939780.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+85bae1...@syzkaller.appspotmail.com

loop1: detected capacity change from 0 to 512
ext4 filesystem being mounted at /111/file0 supports timestamps until 2038-01-19 (0x7fffffff)
==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / move_expired_inodes

read-write to 0xffff888104e265b8 of 4 bytes by task 28 on cpu 1:
move_expired_inodes+0x17a/0x410 fs/fs-writeback.c:1435
queue_io+0xe1/0x2e0 fs/fs-writeback.c:1487
wb_writeback+0x237/0x640 fs/fs-writeback.c:2130
wb_do_writeback fs/fs-writeback.c:2281 [inline]
wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2321
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 0xffff888104e265b8 of 4 bytes by task 10343 on cpu 0:
__mark_inode_dirty+0x198/0x7e0 fs/fs-writeback.c:2515
mark_inode_dirty include/linux/fs.h:2474 [inline]
dquot_alloc_space include/linux/quotaops.h:319 [inline]
dquot_alloc_block include/linux/quotaops.h:336 [inline]
ext4_mb_new_blocks+0x103e/0x2020 fs/ext4/mballoc.c:6183
ext4_ext_map_blocks+0x1008/0x35c0 fs/ext4/extents.c:4379
ext4_map_create_blocks fs/ext4/inode.c:516 [inline]
ext4_map_blocks+0x592/0xcf0 fs/ext4/inode.c:702
_ext4_get_block+0x104/0x370 fs/ext4/inode.c:781
ext4_get_block_unwritten+0x2c/0xb0 fs/ext4/inode.c:814
ext4_block_write_begin+0x34f/0x9c0 fs/ext4/inode.c:1056
ext4_write_begin+0x426/0xc30
ext4_da_write_begin+0x1b6/0x540 fs/ext4/inode.c:2914
generic_perform_write+0x1a8/0x4a0 mm/filemap.c:4054
ext4_buffered_write_iter+0x1ea/0x370 fs/ext4/file.c:299
ext4_file_write_iter+0x293/0xe10
new_sync_write fs/read_write.c:590 [inline]
vfs_write+0x76a/0x910 fs/read_write.c:683
ksys_write+0xeb/0x1b0 fs/read_write.c:736
__do_sys_write fs/read_write.c:748 [inline]
__se_sys_write fs/read_write.c:745 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:745
x64_sys_call+0x27dd/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:2
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: 0x00000038 -> 0x0001003a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10343 Comm: syz.1.1339 Not tainted 6.12.0-rc3-syzkaller-00217-g4d939780b705 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================
syz.1.1339 (10343) used greatest stack depth: 10232 bytes left


---
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.