[syzbot] [fs?] WARNING in minix_rmdir

[syzbot <syzbot+4e49728ec1cbaf3b91d2@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    8155b4ef3466 Add linux-next specific files for 20241220
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=115656f8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9c90bb7161a56c88
dashboard link: https://syzkaller.appspot.com/bug?extid=4e49728ec1cbaf3b91d2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16726edf980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17535418580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98a974fc662d/disk-8155b4ef.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2dea9b72f624/vmlinux-8155b4ef.xz
kernel image: https://storage.googleapis.com/syzbot-assets/593a42b9eb34/bzImage-8155b4ef.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7d86236cea0c/mount_0.gz

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=122c7418580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=112c7418580000
console output: https://syzkaller.appspot.com/x/log.txt?x=162c7418580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4e49728ec1cbaf3b91d2@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5830 at fs/inode.c:407 drop_nlink+0xc4/0x110 fs/inode.c:407
Modules linked in:
CPU: 0 UID: 0 PID: 5830 Comm: syz-executor235 Not tainted 6.13.0-rc3-next-20241220-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:drop_nlink+0xc4/0x110 fs/inode.c:407
Code: bb 70 07 00 00 be 08 00 00 00 e8 87 15 e7 ff f0 48 ff 83 70 07 00 00 5b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc e8 4d 97 80 ff 90 <0f> 0b 90 eb 83 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 5c ff ff ff
RSP: 0018:ffffc90003ecfd30 EFLAGS: 00010293
RAX: ffffffff823e8cd3 RBX: 1ffff1100ef7ca0c RCX: ffff88803493bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff823e8c53 R09: 1ffffffff203563e
R10: dffffc0000000000 R11: fffffbfff203563f R12: ffff888077be5060
R13: ffff8880792a5a70 R14: ffff888077be5018 R15: dffffc0000000000
FS:  0000555592c31380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe52599f9c CR3: 0000000076e2e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_dec_link_count include/linux/fs.h:2567 [inline]
 minix_rmdir+0xa5/0xc0 fs/minix/namei.c:170
 vfs_rmdir+0x3a3/0x510 fs/namei.c:4394
 do_rmdir+0x3b5/0x580 fs/namei.c:4453
 __do_sys_rmdir fs/namei.c:4472 [inline]
 __se_sys_rmdir fs/namei.c:4470 [inline]
 __x64_sys_rmdir+0x47/0x50 fs/namei.c:4470
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0206e3d47
Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 54 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe52599f88 EFLAGS: 00000207 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb0206e3d47
RDX: 0000000000008890 RSI: 0000000000000000 RDI: 00007ffe5259b130
RBP: 0000000000000065 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffe5259b130
R13: 0000555592c42740 R14: 431bde82d7b634db R15: 00007ffe5259d2b0
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup