------------[ 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.3.1808/20268
WARNING: kernel/locking/rtmutex_common.h:193 at rt_mutex_slowunlock+0x6d9/0x8b0 kernel/locking/rtmutex.c:1428, CPU#0: syz.3.1808/20268
Modules linked in:
CPU: 0 UID: 0 PID: 20268 Comm: syz.3.1808 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:debug_rt_mutex_unlock kernel/locking/rtmutex_common.h:193 [inline]
RIP: 0010:rt_mutex_slowunlock+0x6e0/0x8b0 kernel/locking/rtmutex.c:1428
Code: 88 8f 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 83 3d 74 eb 6a 04 00 75 13 48 8d 3d 07 fa 6d 04 48 c7 c6 e0 f2 4c 8b <67> 48 0f b9 3a 90 e9 2a fa ff ff 90 0f 0b 90 e9 4c fe ff ff be 02
RSP: 0018:ffffc900050c7c00 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880594b8b38 RCX: 0000000000080000
RDX: ffffc90007132000 RSI: ffffffff8b4cf2e0 RDI: ffffffff8f8c03b0
RBP: ffffc900050c7cf0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f11ea3 R12: dffffc0000000000
R13: 1ffff92000a18f88 R14: 0000000000000246 R15: ffff8880594b8ae8
FS: 00007fca2f18d6c0(0000) GS:ffff888126179000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fca2f18cff8 CR3: 00000000a0be0000 CR4: 00000000003526f0
Call Trace:
<TASK>
inode_unlock include/linux/fs.h:1039 [inline]
__unlock_mount fs/namespace.c:2803 [inline]
unlock_mount fs/namespace.c:2813 [inline]
do_loopback+0x402/0x6c0 fs/namespace.c:3030
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
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: 0033:0x7fca30f5cdd9
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:00007fca2f18d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fca311d6090 RCX: 00007fca30f5cdd9
RDX: 0000000000000000 RSI: 0000200000000300 RDI: 0000200000000100
RBP: 00007fca30ff2d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002151090 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fca311d6128 R14: 00007fca311d6090 R15: 00007ffc8f7b7ed8
</TASK>
----------------
Code disassembly (best guess):
0: 88 8f 48 c1 e8 03 mov %cl,0x3e8c148(%rdi)
6: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax
b: 84 c0 test %al,%al
d: 0f 85 c0 01 00 00 jne 0x1d3
13: 83 3d 74 eb 6a 04 00 cmpl $0x0,0x46aeb74(%rip) # 0x46aeb8e
1a: 75 13 jne 0x2f
1c: 48 8d 3d 07 fa 6d 04 lea 0x46dfa07(%rip),%rdi # 0x46dfa2a
23: 48 c7 c6 e0 f2 4c 8b mov $0xffffffff8b4cf2e0,%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 90 nop
30: e9 2a fa ff ff jmp 0xfffffa5f
35: 90 nop
36: 0f 0b ud2
38: 90 nop
39: e9 4c fe ff ff jmp 0xfffffe8a
3e: be .byte 0xbe
3f: 02 .byte 0x2