[syzbot] [nilfs?] WARNING in nilfs_rename (2)

[syzbot <syzbot+f6c7e1f1809f235eeb90@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    b19a97d57c15 Merge tag 'pull-fixes' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1485e6f0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a7016efe6aaa498c
dashboard link: https://syzkaller.appspot.com/bug?extid=f6c7e1f1809f235eeb90
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-b19a97d5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/873500da1a4e/vmlinux-b19a97d5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2e4fbb7fb070/bzImage-b19a97d5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f6c7e1f1809f235eeb90@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 2048
NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 1024)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5356 at fs/inode.c:417 drop_nlink+0xc5/0x110 fs/inode.c:417
Modules linked in:
CPU: 0 UID: 0 PID: 5356 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:drop_nlink+0xc5/0x110 fs/inode.c:417
Code: 78 07 00 00 be 08 00 00 00 e8 d7 f0 e7 ff 3e 48 ff 83 78 07 00 00 5b 41 5c 41 5e 41 5f 5d e9 82 96 41 09 cc e8 3c 06 83 ff 90 <0f> 0b 90 eb 81 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 5b ff ff ff
RSP: 0018:ffffc9000d6879f0 EFLAGS: 00010283
RAX: ffffffff823cb4a4 RBX: ffff88804461bab8 RCX: 0000000000100000
RDX: ffffc9000e58a000 RSI: 000000000000096c RDI: 000000000000096d
RBP: 0000000000000000 R08: ffffffff8fa3a437 R09: 1ffffffff1f47486
R10: dffffc0000000000 R11: fffffbfff1f47487 R12: 1ffff110088c3760
R13: ffff88804461adf8 R14: ffff88804461bb00 R15: dffffc0000000000
FS:  00007f40b8f4e6c0(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 0000000043cee000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nilfs_rename+0x46a/0x820 fs/nilfs2/namei.c:418
 vfs_rename+0xbd7/0xf00 fs/namei.c:5129
 do_renameat2+0x6ce/0xa80 fs/namei.c:5278
 __do_sys_rename fs/namei.c:5325 [inline]
 __se_sys_rename fs/namei.c:5323 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5323
 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: 0033:0x7f40b818ebe9
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:00007f40b8f4e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f40b83b5fa0 RCX: 00007f40b818ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000200000000000
RBP: 00007f40b8211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f40b83b6038 R14: 00007f40b83b5fa0 R15: 00007ffc1ce1df48
 </TASK>


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