------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem)): count = 0x0, magic = 0xffff8880446414e8, owner = 0x0, curr 0xffff888000a72440, list empty
WARNING: CPU: 0 PID: 5366 at kernel/locking/rwsem.c:1265 __down_read_common kernel/locking/rwsem.c:1265 [inline]
WARNING: CPU: 0 PID: 5366 at kernel/locking/rwsem.c:1265 __down_read kernel/locking/rwsem.c:1274 [inline]
WARNING: CPU: 0 PID: 5366 at kernel/locking/rwsem.c:1265 down_read+0x2b1/0x2e0 kernel/locking/rwsem.c:1539
Modules linked in:
CPU: 0 UID: 0 PID: 5366 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~bpo12+1 04/01/2014
RIP: 0010:__down_read_common kernel/locking/rwsem.c:1265 [inline]
RIP: 0010:__down_read kernel/locking/rwsem.c:1274 [inline]
RIP: 0010:down_read+0x2b1/0x2e0 kernel/locking/rwsem.c:1539
Code: 4c 0f 44 d0 48 c7 c7 60 ec 8a 8b 48 c7 c6 00 ed 8a 8b 4c 89 f2 4c 89 f9 4d 89 e0 4d 89 e9 41 52 e8 34 76 05 f6 48 83 c4 08 90 <0f> 0b 90 90 e9 7c fe ff ff 48 c7 c1 64 f1 a3 8f 80 e1 07 80 c1 03
RSP: 0018:ffffc9000d407ad8 EFLAGS: 00010286
RAX: c5981bf476df1000 RBX: ffff888044641540 RCX: ffff888000a72440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1f4 R12: 0000000000000000
R13: ffff888000a72440 R14: 0000000000000000 R15: ffff8880446414e8
FS:  00007f7c0c3b36c0(0000) GS:ffff88808d20c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000042b92000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 inode_lock_shared include/linux/fs.h:884 [inline]
 lookup_slow+0x46/0x70 fs/namei.c:1824
 walk_component+0x2d2/0x400 fs/namei.c:2129
 lookup_last fs/namei.c:2630 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2654
 filename_lookup+0x212/0x570 fs/namei.c:2683
 user_path_at+0x3a/0x60 fs/namei.c:3127
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x2d3/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c0ff8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7c0c3b3038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f7c101c6180 RCX: 00007f7c0ff8ebe9
RDX: 0000200000000300 RSI: 00002000000002c0 RDI: 0000000000000000
RBP: 00007f7c10011e19 R08: 0000200000000340 R09: 0000000000000000
R10: 0000000002008000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c101c6218 R14: 00007f7c101c6180 R15: 00007ffc0f904cd8
 </TASK>