------------[ 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#1: syz.2.123/6521
WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock+0x734/0xa30 kernel/locking/rtmutex.c:1432, CPU#1: syz.2.123/6521
Modules linked in:
CPU: 1 UID: 0 PID: 6521 Comm: syz.2.123 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:193 [inline]
RIP: 0010:rt_mutex_slowunlock+0x73b/0xa30 kernel/locking/rtmutex.c:1432
Code: b2 8f 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 cf 02 00 00 83 3d b9 e4 58 04 00 75 13 48 8d 3d 4c d7 5b 04 48 c7 c6 a0 2a 6d 8b <67> 48 0f b9 3a 90 e9 cf f9 ff ff 48 8d 3d 43 d7 5b 04 67 48 0f b9
RSP: 0018:ffffc9000744fc00 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880610bc0f0 RCX: 0000000000080000
RDX: ffffc90012bc2000 RSI: ffffffff8b6d2aa0 RDI: ffffffff8fb51a60
RBP: ffffc9000744fcf0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f644f9 R12: dffffc0000000000
R13: 1ffff92000e89f88 R14: ffff8880610bc0a0 R15: 0000000000000246
FS:  00007f4478c746c0(0000) GS:ffff888125cc8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4478851d58 CR3: 000000003bdec000 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:3038
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4374
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f447aa5e159
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:00007f4478c74028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f447ace6180 RCX: 00007f447aa5e159
RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000200000000280
RBP: 00007f447aaf506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000101091 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f447ace6218 R14: 00007f447ace6180 R15: 00007ffc81063058
 </TASK>
----------------
Code disassembly (best guess):
   0:	b2 8f                	mov    $0x8f,%dl
   2:	48 c1 e8 03          	shr    $0x3,%rax
   6:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
   b:	84 c0                	test   %al,%al
   d:	0f 85 cf 02 00 00    	jne    0x2e2
  13:	83 3d b9 e4 58 04 00 	cmpl   $0x0,0x458e4b9(%rip)        # 0x458e4d3
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d 4c d7 5b 04 	lea    0x45bd74c(%rip),%rdi        # 0x45bd76f
  23:	48 c7 c6 a0 2a 6d 8b 	mov    $0xffffffff8b6d2aa0,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 cf f9 ff ff       	jmp    0xfffffa04
  35:	48 8d 3d 43 d7 5b 04 	lea    0x45bd743(%rip),%rdi        # 0x45bd77f
  3c:	67                   	addr32
  3d:	48                   	rex.W
  3e:	0f                   	.byte 0xf
  3f:	b9                   	.byte 0xb9