syzbot


possible deadlock in jbd2_log_wait_commit (2)

Status: upstream: reported C repro on 2025/12/20 23:03
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+55a4f0c293a8380cba64@syzkaller.appspotmail.com
First crash: 138d, last: 8h39m
Bug presence (2)
Date Name Commit Repro Result
2026/04/26 linux-5.15.y (ToT) b9d57c40a767 C [report] possible deadlock in jbd2_log_wait_commit
2026/04/26 upstream (ToT) 897d54018cc9 C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in jbd2_log_wait_commit 4 29 317d 515d 0/3 auto-obsoleted due to no activity on 2025/09/29 15:37
linux-6.1 possible deadlock in jbd2_log_wait_commit 4 2 34d 51d 0/3 upstream: reported on 2026/03/17 07:14
upstream possible deadlock in jbd2_log_wait_commit ext4 4 C done 429 1140d 1164d 22/29 fixed on 2023/06/08 14:41
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/04/27 18:06 13m fix candidate upstream error job log

Sample crash report:
(syz-executor,4345,1):_ocfs2_free_suballoc_bits:2489 ERROR: status = -30
(syz-executor,4345,1):_ocfs2_free_clusters:2583 ERROR: status = -30
(syz-executor,4345,1):ocfs2_replay_truncate_records:5974 ERROR: status = -30
(syz-executor,4345,1):__ocfs2_flush_truncate_log:6055 ERROR: status = -30
(syz-executor,4345,1):ocfs2_sync_fs:405 ERROR: status = -30
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz-executor/4345 is trying to acquire lock:
ffff8880794d8990 (jbd2_handle){++++}-{0:0}, at: jbd2_log_wait_commit+0x14c/0x4c0 fs/jbd2/journal.c:697

but task is already holding lock:
ffff8880794d8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x134c/0x15c0 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/4345:
 #0: ffff88807af9e0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
 #1: ffff88807af9e650 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_replay_truncate_records fs/ocfs2/alloc.c:5938 [inline]
 #1: ffff88807af9e650 (sb_internal#2){.+.+}-{0:0}, at: __ocfs2_flush_truncate_log+0x4a5/0x1110 fs/ocfs2/alloc.c:6052
 #2: ffff8880798358e8 (&journal->j_trans_barrier){.+.+}-{3:3}, at: ocfs2_start_trans+0x3a6/0x6f0 fs/ocfs2/journal.c:374
 #3: ffff8880794d8990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x134c/0x15c0 fs/jbd2/transaction.c:462

stack backtrace:
CPU: 1 PID: 4345 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 __lock_acquire+0x1236/0x7d10 kernel/locking/lockdep.c:-1
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 jbd2_log_wait_commit+0x168/0x4c0 fs/jbd2/journal.c:697
 ocfs2_sync_fs+0x21d/0x330 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+0x42d/0x4e0 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: 0033:0x7ff252768017
Code: a2 c7 05 dc 06 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe4c29f178 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007ff2527fc120 RCX: 00007ff252768017
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe4c29f230
RBP: 00007ffe4c29f230 R08: 00007ffe4c2a0230 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe4c2a02c0
R13: 00007ff2527fc120 R14: 0000000000014cc2 R15: 00007ffe4c2a0300
 </TASK>

Crashes (278):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/03 06:26 linux-5.15.y ef251c45f1cd a0d91488 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/02 01:45 linux-5.15.y ef251c45f1cd 753c55b9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 17:47 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/25 10:07 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/07 15:27 linux-5.15.y ef251c45f1cd cbf9e0fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/07 04:37 linux-5.15.y ef251c45f1cd f250db59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/06 14:27 linux-5.15.y ef251c45f1cd 1dddfd3d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/05 13:24 linux-5.15.y ef251c45f1cd 06e69a27 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/05 01:36 linux-5.15.y ef251c45f1cd a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/04 21:31 linux-5.15.y ef251c45f1cd a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/04 21:30 linux-5.15.y ef251c45f1cd a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/04 13:54 linux-5.15.y ef251c45f1cd 85f1bcf2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/04 12:23 linux-5.15.y ef251c45f1cd 85f1bcf2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/04 07:21 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 19:26 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 12:29 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 10:27 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 06:13 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 05:34 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 05:11 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 04:53 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 03:52 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 03:41 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/03 00:48 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/02 20:33 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/02 11:15 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/02 08:35 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/01 22:56 linux-5.15.y ef251c45f1cd 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/01 09:13 linux-5.15.y ef251c45f1cd 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/05/01 09:11 linux-5.15.y ef251c45f1cd 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/28 10:30 linux-5.15.y b9d57c40a767 ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 23:17 linux-5.15.y b9d57c40a767 ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 16:04 linux-5.15.y b9d57c40a767 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 11:53 linux-5.15.y b9d57c40a767 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 11:53 linux-5.15.y b9d57c40a767 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 07:41 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 05:41 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/27 01:52 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 23:35 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 19:23 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 14:06 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 08:08 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 04:10 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 02:10 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 01:56 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 01:40 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 01:40 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2026/04/26 01:40 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
2025/12/20 23:02 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in jbd2_log_wait_commit
* Struck through repros no longer work on HEAD.