syzbot


possible deadlock in ocfs2_xattr_remove

Status: upstream: reported on 2026/01/22 16:49
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+7df4afa14aeda476a7a1@syzkaller.appspotmail.com
First crash: 98d, last: 17h25m
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in ocfs2_xattr_remove 0 (1) 2026/01/22 16:49

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.951/17109 is trying to acquire lock:
ffff888066e71c40 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
ffff888066e71c40 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_xattr_free_block fs/ocfs2/xattr.c:2556 [inline]
ffff888066e71c40 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_xattr_remove+0x94e/0x1650 fs/ocfs2/xattr.c:2631

but task is already holding lock:
ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:854 [inline]
ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xe97/0x4390 fs/ocfs2/inode.c:1299

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}:
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1625
       inode_lock include/linux/fs.h:1029 [inline]
       ocfs2_del_inode_from_orphan+0x12e/0x7a0 fs/ocfs2/namei.c:2728
       ocfs2_dio_end_io_write fs/ocfs2/aops.c:2379 [inline]
       ocfs2_dio_end_io+0xf9e/0x1370 fs/ocfs2/aops.c:2418
       dio_complete+0x25e/0x790 fs/direct-io.c:281
       __blockdev_direct_IO+0x2e12/0x3470 fs/direct-io.c:1303
       ocfs2_direct_IO+0x253/0x2c0 fs/ocfs2/aops.c:2455
       generic_file_direct_write+0x1dc/0x3e0 mm/filemap.c:4259
       __generic_file_write_iter+0x120/0x240 mm/filemap.c:4428
       ocfs2_file_write_iter+0x1666/0x1e70 fs/ocfs2/file.c:2476
       do_iter_readv_writev+0x62b/0x8d0 fs/read_write.c:-1
       vfs_writev+0x345/0x9a0 fs/read_write.c:1059
       do_writev+0x15a/0x2e0 fs/read_write.c:1105
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1625
       inode_lock include/linux/fs.h:1029 [inline]
       ocfs2_xattr_free_block fs/ocfs2/xattr.c:2556 [inline]
       ocfs2_xattr_remove+0x94e/0x1650 fs/ocfs2/xattr.c:2631
       ocfs2_wipe_inode fs/ocfs2/inode.c:884 [inline]
       ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
       ocfs2_evict_inode+0x140b/0x4390 fs/ocfs2/inode.c:1299
       evict+0x61e/0xb10 fs/inode.c:841
       d_delete_notify include/linux/fsnotify.h:377 [inline]
       vfs_rmdir+0x42d/0x6f0 fs/namei.c:5379
       filename_rmdir+0x292/0x520 fs/namei.c:5421
       __do_sys_unlinkat fs/namei.c:5596 [inline]
       __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5589
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
                               lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);
                               lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
  lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);

 *** DEADLOCK ***

4 locks held by syz.7.951/17109:
 #0: ffff88802a80c480 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888061a71c40 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
 #1: ffff888061a71c40 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline]
 #1: ffff888061a71c40 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline]
 #1: ffff888061a71c40 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5414
 #2: ffff88805dbece30 (&osb->nfs_sync_rwlock){++++}-{4:4}, at: ocfs2_nfs_sync_lock+0x106/0x270 fs/ocfs2/dlmglue.c:2875
 #3: ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #3: ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:854 [inline]
 #3: ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 #3: ffff888066e72d00 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xe97/0x4390 fs/ocfs2/inode.c:1299

stack backtrace:
CPU: 1 UID: 0 PID: 17109 Comm: syz.7.951 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 down_write+0x3a/0x50 kernel/locking/rwsem.c:1625
 inode_lock include/linux/fs.h:1029 [inline]
 ocfs2_xattr_free_block fs/ocfs2/xattr.c:2556 [inline]
 ocfs2_xattr_remove+0x94e/0x1650 fs/ocfs2/xattr.c:2631
 ocfs2_wipe_inode fs/ocfs2/inode.c:884 [inline]
 ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 ocfs2_evict_inode+0x140b/0x4390 fs/ocfs2/inode.c:1299
 evict+0x61e/0xb10 fs/inode.c:841
 d_delete_notify include/linux/fsnotify.h:377 [inline]
 vfs_rmdir+0x42d/0x6f0 fs/namei.c:5379
 filename_rmdir+0x292/0x520 fs/namei.c:5421
 __do_sys_unlinkat fs/namei.c:5596 [inline]
 __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5589
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc61e54cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc61c79e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fc61e7c5fa0 RCX: 00007fc61e54cdd9
RDX: 0000000000000200 RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007fc61e5e2d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc61e7c6038 R14: 00007fc61e7c5fa0 R15: 00007fffa04805e8
 </TASK>

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/26 01:17 upstream 897d54018cc9 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/25 14:39 upstream 27d128c1cff6 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 21:42 upstream faeab166167f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 11:34 upstream faeab166167f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 11:06 upstream faeab166167f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 11:02 upstream faeab166167f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 11:02 upstream faeab166167f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 04:47 upstream eb5249b12507 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/19 03:11 upstream eb5249b12507 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/18 13:37 upstream 8541d8f725c6 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/18 07:54 upstream 8541d8f725c6 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/17 22:56 upstream 43cfbdda5af6 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/04/17 21:25 upstream 43cfbdda5af6 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_xattr_remove
2026/01/18 16:45 upstream 54e82e93ca93 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_xattr_remove
* Struck through repros no longer work on HEAD.