------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)
WARNING: kernel/locking/rtmutex_common.h:193 at debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:193 [inline], CPU#0: syz.8.309/9012
WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock+0x732/0xa20 kernel/locking/rtmutex.c:1432, CPU#0: syz.8.309/9012
Modules linked in:
CPU: 0 UID: 0 PID: 9012 Comm: syz.8.309 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:193 [inline]
RIP: 0010:rt_mutex_slowunlock+0x739/0xa20 kernel/locking/rtmutex.c:1432
Code: af 8f 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 cf 02 00 00 83 3d db f7 6b 04 00 75 13 48 8d 3d 3e 3c 6f 04 48 c7 c6 a0 ff 6c 8b <67> 48 0f b9 3a 90 e9 d1 f9 ff ff 48 8d 3d 35 3c 6f 04 67 48 0f b9
RSP: 0018:ffffc90003927c00 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff888062e36df0 RCX: 0000000000080000
RDX: ffffc9001d1dc000 RSI: ffffffff8b6cffa0 RDI: ffffffff8fb2d7b0
RBP: ffffc90003927cf0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f5f269 R12: dffffc0000000000
R13: 1ffff92000724f88 R14: ffff888062e36da0 R15: 0000000000000246
FS:  00007f41064046c0(0000) GS:ffff888125c49000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30018ff8 CR3: 0000000061426000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:1034 [inline]
 __unlock_mount fs/namespace.c:2808 [inline]
 unlock_mount fs/namespace.c:2818 [inline]
 do_loopback+0x404/0x6c0 fs/namespace.c:3035
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f41081ede59
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:00007f4106404028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f4108476180 RCX: 00007f41081ede59
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000200000000000
RBP: 00007f4108283e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000981446 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4108476218 R14: 00007f4108476180 R15: 00007ffdbe6db3f8
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	48 c1 e8 03          	shr    $0x3,%rax
   4:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
   9:	84 c0                	test   %al,%al
   b:	0f 85 cf 02 00 00    	jne    0x2e0
  11:	83 3d db f7 6b 04 00 	cmpl   $0x0,0x46bf7db(%rip)        # 0x46bf7f3
  18:	75 13                	jne    0x2d
  1a:	48 8d 3d 3e 3c 6f 04 	lea    0x46f3c3e(%rip),%rdi        # 0x46f3c5f
  21:	48 c7 c6 a0 ff 6c 8b 	mov    $0xffffffff8b6cffa0,%rsi
* 28:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2d:	90                   	nop
  2e:	e9 d1 f9 ff ff       	jmp    0xfffffa04
  33:	48 8d 3d 35 3c 6f 04 	lea    0x46f3c35(%rip),%rdi        # 0x46f3c6f
  3a:	67                   	addr32
  3b:	48                   	rex.W
  3c:	0f                   	.byte 0xf
  3d:	b9                   	.byte 0xb9