syzbot


possible deadlock in __ocfs2_flush_truncate_log

Status: upstream: reported on 2025/03/14 12:11
Reported-by: syzbot+8ee11b9169d68fdff162@syzkaller.appspotmail.com
First crash: 417d, last: 2d17h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in __ocfs2_flush_truncate_log ocfs2 4 C inconclusive 3410 267d 416d 29/29 fixed on 2025/09/04 16:57
linux-6.6 possible deadlock in __ocfs2_flush_truncate_log origin:upstream missing-backport 4 C inconclusive 548 3d21h 313d 0/2 upstream: reported C repro on 2025/06/27 02:38
linux-5.15 possible deadlock in __ocfs2_flush_truncate_log 4 832 2d17h 417d 0/3 upstream: reported on 2025/03/14 17:58

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:8/4444 is trying to acquire lock:
ffff88806fdac2c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff88806fdac2c8 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: __ocfs2_flush_truncate_log+0x36a/0x1220 fs/ocfs2/alloc.c:6046

but task is already holding lock:
ffff88806fd92648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff88806fd92648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_flush_truncate_log fs/ocfs2/alloc.c:6075 [inline]
ffff88806fd92648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_truncate_log_worker+0x97/0x190 fs/ocfs2/alloc.c:6089

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}:
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       ocfs2_move_extent fs/ocfs2/move_extents.c:646 [inline]
       __ocfs2_move_extents_range+0x1a5f/0x35d0 fs/ocfs2/move_extents.c:866
       ocfs2_move_extents+0x3ad/0x9c0 fs/ocfs2/move_extents.c:938
       ocfs2_ioctl_move_extents+0x520/0x6c0 fs/ocfs2/move_extents.c:1064
       ocfs2_ioctl+0x31e/0x7c0 fs/ocfs2/ioctl.c:930
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       __ocfs2_flush_truncate_log+0x36a/0x1220 fs/ocfs2/alloc.c:6046
       ocfs2_flush_truncate_log fs/ocfs2/alloc.c:6076 [inline]
       ocfs2_truncate_log_worker+0x9f/0x190 fs/ocfs2/alloc.c:6089
       process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
       worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
       kthread+0x29d/0x330 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6);
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);

 *** DEADLOCK ***

3 locks held by kworker/u4:8/4444:
 #0: ffff888027b2d938 ((wq_completion)ocfs2_wq){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
 #1: ffffc90004d3fd00 ((work_completion)(&(&osb->osb_truncate_log_wq)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
 #2: ffff88806fd92648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff88806fd92648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_flush_truncate_log fs/ocfs2/alloc.c:6075 [inline]
 #2: ffff88806fd92648 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#6){+.+.}-{3:3}, at: ocfs2_truncate_log_worker+0x97/0x190 fs/ocfs2/alloc.c:6089

stack backtrace:
CPU: 1 PID: 4444 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: ocfs2_wq ocfs2_truncate_log_worker
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:758 [inline]
 __ocfs2_flush_truncate_log+0x36a/0x1220 fs/ocfs2/alloc.c:6046
 ocfs2_flush_truncate_log fs/ocfs2/alloc.c:6076 [inline]
 ocfs2_truncate_log_worker+0x9f/0x190 fs/ocfs2/alloc.c:6089
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (2636):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/03 14:31 linux-6.1.y 4931e0e1673d a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/05/01 23:59 linux-6.1.y 4931e0e1673d 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/04/25 07:12 linux-6.1.y 7c87defbd336 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/04/23 06:22 linux-6.1.y 7c87defbd336 b10da5ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/04/22 07:32 linux-6.1.y 7c87defbd336 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/04/19 01:14 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/04/17 21:11 linux-6.1.y 8e8fc038cad5 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/03/08 23:04 linux-6.1.y f2ddafa93a25 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/03/08 21:27 linux-6.1.y f2ddafa93a25 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/03/01 02:12 linux-6.1.y 779f9571ac3e 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/02/15 00:14 linux-6.1.y 8ce36b2849ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/02/11 17:46 linux-6.1.y 8ce36b2849ef 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/02/11 01:52 linux-6.1.y 0182cb5b74ee 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/02/10 13:11 linux-6.1.y 0182cb5b74ee 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/02/05 07:02 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2026/03/12 07:20 linux-6.1.y f2ddafa93a25 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/02/05 19:52 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/02/05 18:12 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/02/05 18:12 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/02/05 15:35 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/25 22:34 linux-6.1.y cd9b81672742 55756628 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/24 11:37 linux-6.1.y cd9b81672742 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/24 00:17 linux-6.1.y cd9b81672742 4f25b9b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/23 11:52 linux-6.1.y cd9b81672742 e2b1b6e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/23 11:49 linux-6.1.y cd9b81672742 e2b1b6e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/23 07:49 linux-6.1.y cd9b81672742 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/22 19:18 linux-6.1.y cd9b81672742 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/22 07:12 linux-6.1.y cd9b81672742 a16aed1d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/21 18:46 linux-6.1.y cd9b81672742 8fc37797 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/21 13:38 linux-6.1.y cd9b81672742 6f1aa2f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/21 02:00 linux-6.1.y cd9b81672742 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/21 02:00 linux-6.1.y cd9b81672742 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/20 21:16 linux-6.1.y cd9b81672742 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/17 02:48 linux-6.1.y bec0e10ee67e 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/17 01:00 linux-6.1.y bec0e10ee67e 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/16 10:24 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/16 06:51 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/15 23:40 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/15 16:30 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/15 16:29 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/15 14:19 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/14 18:48 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/13 06:52 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/12 03:38 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/11 19:24 linux-6.1.y bec0e10ee67e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/11 07:28 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/11 06:18 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/10 20:32 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/10 19:14 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/10 13:15 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2026/01/10 11:04 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/03/14 12:10 linux-6.1.y 344a09659766 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
* Struck through repros no longer work on HEAD.