loop0: detected capacity change from 0 to 4096
process 'syz.0.0' launched './file2' with NULL argv: empty string added
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5321 at fs/inode.c:474 inc_nlink+0x122/0x150 fs/inode.c:474
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~bpo12+1 04/01/2014
RIP: 0010:inc_nlink+0x122/0x150 fs/inode.c:474
Code: e7 ff e9 3a ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 4c ff ff ff 48 89 df e8 29 d1 e7 ff e9 3f ff ff ff e8 5f 92 80 ff 90 <0f> 0b 90 eb 80 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 50 ff ff ff
RSP: 0018:ffffc9000d2e73c8 EFLAGS: 00010287
RAX: ffffffff823f83d1 RBX: ffff88804330f420 RCX: 0000000000100000
RDX: ffffc9000e2c2000 RSI: 0000000000001abf RDI: 0000000000001ac0
RBP: 0000000000000000 R08: ffffffff8f7cfb77 R09: 1ffffffff1ef9f6e
R10: dffffc0000000000 R11: fffffbfff1ef9f6f R12: dffffc0000000000
R13: 1ffff11008661e84 R14: ffff88804330f3d8 R15: ffff88804330f4a8
FS:  00007f3a109b76c0(0000) GS:ffff88808d732000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000010c0 CR3: 0000000042aef000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nilfs_mkdir+0xf6/0x330 fs/nilfs2/namei.c:232
 vfs_mkdir+0x306/0x510 fs/namei.c:4453
 ovl_do_mkdir fs/overlayfs/overlayfs.h:251 [inline]
 ovl_workdir_create+0x4c3/0x8b0 fs/overlayfs/super.c:340
 ovl_make_workdir fs/overlayfs/super.c:679 [inline]
 ovl_get_workdir+0x32b/0x17b0 fs/overlayfs/super.c:837
 ovl_fill_super+0x154a/0x3da0 fs/overlayfs/super.c:1468
 vfs_get_super fs/super.c:1324 [inline]
 get_tree_nodev+0xbb/0x150 fs/super.c:1343
 vfs_get_tree+0x92/0x2b0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3727
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x313/0x410 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a0fb8f6c9
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:00007f3a109b7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f3a0fde5fa0 RCX: 00007f3a0fb8f6c9
RDX: 0000200000000b80 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f3a0fc11f91 R08: 0000200000000180 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3a0fde6038 R14: 00007f3a0fde5fa0 R15: 00007ffde9e291b8
 </TASK>