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: 172d, last: 4h52m
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 22d 171d 28/29 upstream: reported C repro on 2025/03/15 11:28
linux-6.6 possible deadlock in __ocfs2_flush_truncate_log origin:upstream missing-backport 4 C 166 16h27m 67d 0/2 upstream: reported C repro on 2025/06/27 02:38
linux-5.15 possible deadlock in __ocfs2_flush_truncate_log 4 668 16h45m 172d 0/3 upstream: reported on 2025/03/14 17:58

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.1.148-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/4260 is trying to acquire lock:
ffff8880705f9808 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880705f9808 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{3:3}, at: __ocfs2_flush_truncate_log+0x34f/0x11d0 fs/ocfs2/alloc.c:6047

but task is already holding lock:
ffff8880706bb488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff8880706bb488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_flush_truncate_log+0x43/0x60 fs/ocfs2/alloc.c:6076

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]#5){+.+.}-{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:640 [inline]
       __ocfs2_move_extents_range+0x1a61/0x3360 fs/ocfs2/move_extents.c:860
       ocfs2_move_extents+0x37c/0x960 fs/ocfs2/move_extents.c:927
       ocfs2_ioctl_move_extents+0x4da/0x6b0 fs/ocfs2/move_extents.c:1053
       ocfs2_ioctl+0x2d7/0x740 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:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4){+.+.}-{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+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 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+0x34f/0x11d0 fs/ocfs2/alloc.c:6047
       ocfs2_flush_truncate_log+0x4b/0x60 fs/ocfs2/alloc.c:6077
       ocfs2_sync_fs+0x113/0x310 fs/ocfs2/super.c:402
       sync_filesystem+0x1be/0x220 fs/sync.c:66
       generic_shutdown_super+0x6b/0x340 fs/super.c:474
       kill_block_super+0x7c/0xe0 fs/super.c:1470
       deactivate_locked_super+0x93/0xf0 fs/super.c:332
       cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182
       task_work_run+0x1ca/0x250 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
       syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
       do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);
                               lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5);
  lock(&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#4);

 *** DEADLOCK ***

2 locks held by syz-executor/4260:
 #0: ffff888076e9a0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
 #1: ffff8880706bb488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff8880706bb488 (&ocfs2_sysfile_lock_key[args->fi_sysfile_type]#5){+.+.}-{3:3}, at: ocfs2_flush_truncate_log+0x43/0x60 fs/ocfs2/alloc.c:6076

stack backtrace:
CPU: 0 PID: 4260 Comm: syz-executor Not tainted 6.1.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 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+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 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+0x34f/0x11d0 fs/ocfs2/alloc.c:6047
 ocfs2_flush_truncate_log+0x4b/0x60 fs/ocfs2/alloc.c:6077
 ocfs2_sync_fs+0x113/0x310 fs/ocfs2/super.c:402
 sync_filesystem+0x1be/0x220 fs/sync.c:66
 generic_shutdown_super+0x6b/0x340 fs/super.c:474
 kill_block_super+0x7c/0xe0 fs/super.c:1470
 deactivate_locked_super+0x93/0xf0 fs/super.c:332
 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1182
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc70fb8ff17
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:00007ffd2eb81f48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc70fc11c05 RCX: 00007fc70fb8ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd2eb82000
RBP: 00007ffd2eb82000 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd2eb83090
R13: 00007fc70fc11c05 R14: 0000000000013367 R15: 00007ffd2eb830d0
 </TASK>
ocfs2: Unmounting device (7,2) on (node local)

Crashes (1283):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/26 08:28 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 07:17 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __ocfs2_flush_truncate_log
2025/09/02 17:31 linux-6.1.y f89b6e15694c 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/02 17:29 linux-6.1.y f89b6e15694c 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/02 16:22 linux-6.1.y f89b6e15694c 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/02 11:35 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/01 19:29 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/01 12:11 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/01 06:04 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/09/01 02:14 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/31 20:02 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/30 21:57 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/30 15:44 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/30 02:15 linux-6.1.y f89b6e15694c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/29 12:30 linux-6.1.y f89b6e15694c 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/29 01:39 linux-6.1.y f89b6e15694c d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/29 01:35 linux-6.1.y f89b6e15694c d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/29 00:28 linux-6.1.y f89b6e15694c d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/28 22:41 linux-6.1.y f89b6e15694c d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/28 12:02 linux-6.1.y 0bc96de781b4 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/27 12:44 linux-6.1.y 0bc96de781b4 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/26 20:00 linux-6.1.y 0bc96de781b4 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/26 19:56 linux-6.1.y 0bc96de781b4 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/26 18:34 linux-6.1.y 0bc96de781b4 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/26 15:03 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/26 03:19 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/25 22:52 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/25 13:47 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/24 20:55 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/24 14:09 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/24 04:48 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 21:03 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 17:44 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 16:43 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 15:08 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 12:42 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 11:47 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 10:25 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 08:15 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/23 01:17 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/22 21:37 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/22 21:09 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in __ocfs2_flush_truncate_log
2025/08/22 07:48 linux-6.1.y 0bc96de781b4 bf27483f .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.