------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888053af8a70, owner = 0x0, curr 0xffff888025bb3d00, list empty
WARNING: kernel/locking/rwsem.c:1381 at __up_write kernel/locking/rwsem.c:1380 [inline], CPU#0: syz.4.214/6857
WARNING: kernel/locking/rwsem.c:1381 at up_write+0x2d6/0x410 kernel/locking/rwsem.c:1643, CPU#0: syz.4.214/6857
Modules linked in:
CPU: 0 UID: 0 PID: 6857 Comm: syz.4.214 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:__up_write kernel/locking/rwsem.c:1380 [inline]
RIP: 0010:up_write+0x388/0x410 kernel/locking/rwsem.c:1643
Code: 8c 8b 49 c7 c2 a0 e6 8c 8b 4c 0f 44 d0 48 8b 7c 24 08 48 c7 c6 00 e9 8c 8b 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 10 41 52 <67> 48 0f b9 3a 48 83 c4 08 e8 7a 30 f6 02 e9 67 fd ff ff 48 c7 c1
RSP: 0018:ffffc9000bb5fc18 EFLAGS: 00010246
RAX: ffffffff8b8ce680 RBX: ffff888053af8a70 RCX: ffff888053af8a70
RDX: 0000000000000000 RSI: ffffffff8b8ce900 RDI: ffffffff8fd21720
RBP: ffff888053af8ac8 R08: 0000000000000000 R09: ffff888025bb3d00
R10: ffffffff8b8ce680 R11: ffffed100a75f150 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888053af8a70 R15: 1ffff1100a75f14f
FS:  00007f906f4016c0(0000) GS:ffff888125928000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ac5f7c000 CR3: 00000000779fb000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:1037 [inline]
 __unlock_mount fs/namespace.c:2786 [inline]
 unlock_mount+0xbd/0x3a0 fs/namespace.c:2796
 do_new_mount_fc fs/namespace.c:3659 [inline]
 do_new_mount+0x75d/0xa50 fs/namespace.c:3712
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4201
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f906e59acb9
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:00007f906f401028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f906e816090 RCX: 00007f906e59acb9
RDX: 0000200000000180 RSI: 0000200000000140 RDI: 0000000000000000
RBP: 00007f906e608bf7 R08: 00002000000003c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f906e816128 R14: 00007f906e816090 R15: 00007fff41bd28e8
 </TASK>
----------------
Code disassembly (best guess):
   0:	8c 8b 49 c7 c2 a0    	mov    %cs,-0x5f3d38b7(%rbx)
   6:	e6 8c                	out    %al,$0x8c
   8:	8b 4c 0f 44          	mov    0x44(%rdi,%rcx,1),%ecx
   c:	d0 48 8b             	rorb   $1,-0x75(%rax)
   f:	7c 24                	jl     0x35
  11:	08 48 c7             	or     %cl,-0x39(%rax)
  14:	c6 00 e9             	movb   $0xe9,(%rax)
  17:	8c 8b 48 8b 14 24    	mov    %cs,0x24148b48(%rbx)
  1d:	4c 89 f1             	mov    %r14,%rcx
  20:	4d 89 e0             	mov    %r12,%r8
  23:	4c 8b 4c 24 10       	mov    0x10(%rsp),%r9
  28:	41 52                	push   %r10
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	e8 7a 30 f6 02       	call   0x2f630b2
  38:	e9 67 fd ff ff       	jmp    0xfffffda4
  3d:	48                   	rex.W
  3e:	c7                   	.byte 0xc7
  3f:	c1                   	.byte 0xc1