------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888043f34328, owner = 0x0, curr 0xffff88803439a580, list not empty
WARNING: kernel/locking/rwsem.c:1413 at __up_write kernel/locking/rwsem.c:1412 [inline], CPU#0: syz.0.0/5321
WARNING: kernel/locking/rwsem.c:1413 at up_write+0x35c/0x4a0 kernel/locking/rwsem.c:1688, CPU#0: syz.0.0/5321
Modules linked in:
CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__up_write kernel/locking/rwsem.c:1412 [inline]
RIP: 0010:up_write+0x40f/0x4a0 kernel/locking/rwsem.c:1688
Code: 0d 8c 49 c7 c2 80 1b 0d 8c 4c 0f 44 d0 48 8b 7c 24 10 48 c7 c6 20 1e 0d 8c 48 8b 14 24 48 8b 4c 24 08 4d 89 e0 4d 89 f9 41 52 <67> 48 0f b9 3a 48 83 c4 08 e8 e3 94 39 03 e9 d6 fc ff ff 48 c7 c1
RSP: 0018:ffffc9000f757c60 EFLAGS: 00010246
RAX: ffffffff8c0d1ba0 RBX: ffff888043f34328 RCX: ffff888043f34328
RDX: 0000000000000000 RSI: ffffffff8c0d1e20 RDI: ffffffff907d6ab0
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffff88803439a580
R10: ffffffff8c0d1ba0 R11: ffffed10087e6867 R12: 0000000000000000
R13: ffff888043f34330 R14: ffff888043f34380 R15: ffff88803439a580
FS:  00007fb2f42c76c0(0000) GS:ffff88808c2cf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f654f035000 CR3: 0000000012328000 CR4: 0000000000352ef0
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_new_mount_fc fs/namespace.c:3795 [inline]
 do_new_mount+0x82d/0xdc0 fs/namespace.c:3848
 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: 0033:0x7fb2f339e159
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:00007fb2f42c6fe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb2f3626090 RCX: 00007fb2f339e159
RDX: 00002000000000c0 RSI: 0000200000000080 RDI: 0000000000000000
RBP: 00007fb2f3435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb2f3626128 R14: 00007fb2f3626090 R15: 00007fff4d9e6078
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	49 c7 c2 80 1b 0d 8c 	mov    $0xffffffff8c0d1b80,%r10
   7:	4c 0f 44 d0          	cmove  %rax,%r10
   b:	48 8b 7c 24 10       	mov    0x10(%rsp),%rdi
  10:	48 c7 c6 20 1e 0d 8c 	mov    $0xffffffff8c0d1e20,%rsi
  17:	48 8b 14 24          	mov    (%rsp),%rdx
  1b:	48 8b 4c 24 08       	mov    0x8(%rsp),%rcx
  20:	4d 89 e0             	mov    %r12,%r8
  23:	4d 89 f9             	mov    %r15,%r9
  26:	41 52                	push   %r10
* 28:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2d:	48 83 c4 08          	add    $0x8,%rsp
  31:	e8 e3 94 39 03       	call   0x3399519
  36:	e9 d6 fc ff ff       	jmp    0xfffffd11
  3b:	48                   	rex.W
  3c:	c7                   	.byte 0xc7
  3d:	c1                   	.byte 0xc1