[v5.15] possible deadlock in jbd2_log_wait_commit (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 68efe5a6c16a Linux 5.15.197
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=174e1392580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e6ed99963d6ee1d
dashboard link: https://syzkaller.appspot.com/bug?extid=55a4f0c293a8380cba64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/900f9b9bd850/disk-68efe5a6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1e089a5019a6/vmlinux-68efe5a6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b319f477b907/bzImage-68efe5a6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+55a4f0...@syzkaller.appspotmail.com

(syz-executor,4180,0):__ocfs2_flush_truncate_log:6056 ERROR: status = -30
(syz-executor,4180,0):ocfs2_sync_fs:405 ERROR: status = -30
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz-executor/4180 is trying to acquire lock:
ffff88802475a990 (jbd2_handle){++++}-{0:0}, at: jbd2_log_wait_commit+0x14e/0x4a0 fs/jbd2/journal.c:697

but task is already holding lock:
ffff88802475a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1312/0x15a0 fs/jbd2/transaction.c:462

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(jbd2_handle);
lock(jbd2_handle);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by syz-executor/4180:
#0: ffff8880799fe0e0 (&type->s_umount_key#57){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
#1: ffff8880799fe650 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_replay_truncate_records fs/ocfs2/alloc.c:5939 [inline]
#1: ffff8880799fe650 (sb_internal#2){.+.+}-{0:0}, at: __ocfs2_flush_truncate_log+0x46a/0x1060 fs/ocfs2/alloc.c:6053
#2: ffff88805f5698e8 (&journal->j_trans_barrier){.+.+}-{3:3}, at: ocfs2_start_trans+0x368/0x6c0 fs/ocfs2/journal.c:374
#3: ffff88802475a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1312/0x15a0 fs/jbd2/transaction.c:462

stack backtrace:
CPU: 0 PID: 4180 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
__lock_acquire+0x1227/0x7c60 kernel/locking/lockdep.c:-1
lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
jbd2_log_wait_commit+0x16a/0x4a0 fs/jbd2/journal.c:697
ocfs2_sync_fs+0x217/0x310 fs/ocfs2/super.c:413
sync_filesystem+0x1be/0x220 fs/sync.c:66
generic_shutdown_super+0x6b/0x300 fs/super.c:448
kill_block_super+0x7c/0xe0 fs/super.c:1427
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x418/0x4d0 fs/namespace.c:1148
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f516976fa77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe336706d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f51697f2d7d RCX: 00007f516976fa77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe33670790
RBP: 00007ffe33670790 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe33671820
R13: 00007f51697f2d7d R14: 000000000001799c R15: 00007ffe33671860
</TASK>


---
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