syzbot


WARNING in ovl_workdir_create (5)

Status: upstream: reported on 2025/09/10 17:53
Subsystems: overlayfs
[Documentation on labels]
Reported-by: syzbot+078954d5ad423349aa78@syzkaller.appspotmail.com
First crash: 40d, last: 16d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [overlayfs?] WARNING in ovl_workdir_create (5) 0 (1) 2025/09/10 17:53
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in ovl_workdir_create (3) -1 2 76d 76d 0/3 upstream: reported on 2025/08/01 02:41
upstream WARNING in ovl_workdir_create overlayfs -1 1 1030d 1026d 0/29 auto-obsoleted due to no activity on 2023/04/20 02:11
upstream WARNING in ovl_workdir_create (3) ext4 -1 1 525d 521d 0/29 auto-obsoleted due to no activity on 2024/08/17 18:22
linux-6.1 WARNING in ovl_workdir_create (3) -1 4 40d 160d 0/3 upstream: reported on 2025/05/09 07:54
upstream WARNING in ovl_workdir_create (4) overlayfs -1 1 325d 321d 0/29 auto-obsoleted due to no activity on 2025/01/24 06:35
linux-6.1 WARNING in ovl_workdir_create (2) -1 2 301d 316d 0/3 auto-obsoleted due to no activity on 2025/03/29 20:32
linux-5.15 WARNING in ovl_workdir_create -1 3 325d 478d 0/3 auto-obsoleted due to no activity on 2025/03/04 23:52
linux-5.15 WARNING in ovl_workdir_create (2) -1 1 196d 196d 0/3 auto-obsoleted due to no activity on 2025/07/12 19:53
linux-6.1 WARNING in ovl_workdir_create -1 1 517d 517d 0/3 auto-obsoleted due to no activity on 2024/08/25 13:40
upstream WARNING in ovl_workdir_create (2) overlayfs -1 1 706d 702d 0/29 auto-obsoleted due to no activity on 2024/02/18 01:53

Sample crash report:
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)
WARNING: CPU: 0 PID: 6095 at kernel/locking/rtmutex_common.h:191 debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:191 [inline]
WARNING: CPU: 0 PID: 6095 at kernel/locking/rtmutex_common.h:191 rt_mutex_slowunlock+0x6ce/0x8a0 kernel/locking/rtmutex.c:1419
Modules linked in:
CPU: 0 UID: 0 PID: 6095 Comm: syz.0.27 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:191 [inline]
RIP: 0010:rt_mutex_slowunlock+0x6ce/0x8a0 kernel/locking/rtmutex.c:1419
Code: 0f b6 04 20 84 c0 0f 85 c6 01 00 00 83 3d ad 8e 02 04 00 75 19 90 48 c7 c7 40 d1 ca 8a 48 c7 c6 80 d1 ca 8a e8 33 98 cd f6 90 <0f> 0b 90 90 90 e9 2f fa ff ff 90 0f 0b 90 e9 53 fe ff ff be 02 00
RSP: 0018:ffffc900056374a0 EFLAGS: 00010046
RAX: f804ebb85cdb5500 RBX: ffff88805ba85830 RCX: 0000000000080000
RDX: ffffc9000f434000 RSI: 000000000000193d RDI: 000000000000193e
RBP: ffffc90005637590 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed101710486b R12: dffffc0000000000
R13: ffff88805ba857e0 R14: 0000000000000a02 R15: 1ffff92000ac6e9c
FS:  00007f794dc1d6c0(0000) GS:ffff888127025000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 00000000296a8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:989 [inline]
 ovl_workdir_create+0x4da/0x8b0 fs/overlayfs/super.c:331
 ovl_make_workdir fs/overlayfs/super.c:669 [inline]
 ovl_get_workdir+0x32b/0x17b0 fs/overlayfs/super.c:827
 ovl_fill_super+0x1365/0x35b0 fs/overlayfs/super.c:1406
 vfs_get_super fs/super.c:1325 [inline]
 get_tree_nodev+0xbb/0x150 fs/super.c:1344
 vfs_get_tree+0x92/0x2b0 fs/super.c:1752
 do_new_mount+0x2a2/0xa30 fs/namespace.c:3750
 do_mount fs/namespace.c:4078 [inline]
 __do_sys_mount fs/namespace.c:4278 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4255
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f794f9deec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f794dc1d038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f794fc36090 RCX: 00007f794f9deec9
RDX: 0000200000000b80 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f794fa61f91 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000004008 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f794fc36128 R14: 00007f794fc36090 R15: 00007ffdfe645bb8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/30 13:26 upstream 1896ce8eb6c6 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in ovl_workdir_create
2025/09/06 17:50 upstream d1d10cea0895 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in ovl_workdir_create
* Struck through repros no longer work on HEAD.