[v6.1] WARNING in minix_rmdir (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bec0e10ee67e Linux 6.1.160
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13d80522580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31ea1cecaf34f0db
dashboard link: https://syzkaller.appspot.com/bug?extid=7f28c102d91fd1e37c83
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0c7c6a53ac77/disk-bec0e10e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/38567d4ccc5b/vmlinux-bec0e10e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5f0a7945f428/Image-bec0e10e.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7f28c1...@syzkaller.appspotmail.com

Trying to free block not in datazone
minix_free_inode: bit 3 already cleared
minix_free_inode: bit 4 already cleared
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4999 at fs/inode.c:332 drop_nlink+0xe4/0x138 fs/inode.c:332
Modules linked in:
CPU: 1 PID: 4999 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : drop_nlink+0xe4/0x138 fs/inode.c:332
lr : drop_nlink+0xe4/0x138 fs/inode.c:332
sp : ffff800020607b00
x29: ffff800020607b00 x28: ffff0000d74c8000 x27: 1fffe0001c3fea9f
x26: ffff800020607b40 x25: 1ffff000040c0f68 x24: dfff800000000000
x23: 1fffe0001ecaa363 x22: dfff800000000000 x21: 0000000000000000
x20: ffff0000f6551b18 x19: ffff0000f6551ad0 x18: 0000000000000000
x17: ffff800018186000 x16: ffff8000082d4a88 x15: 0000000000000000
x14: 000000003b9aca00 x13: 0000000000000000 x12: 0000000000ff0100
x11: ff008000089ff18c x10: 0000000000000000 x9 : ffff8000089ff18c
x8 : ffff0000d74c8000 x7 : 0000000000000000 x6 : 0000000000000052
x5 : ffff0000f6551b58 x4 : ffff0000f65500c8 x3 : ffff8000089ff160
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
drop_nlink+0xe4/0x138 fs/inode.c:332
inode_dec_link_count include/linux/fs.h:2582 [inline]
minix_rmdir+0x164/0x1c0 fs/minix/namei.c:181
vfs_rmdir+0x304/0x438 fs/namei.c:4199
do_rmdir+0x238/0x50c fs/namei.c:4260
__do_sys_unlinkat fs/namei.c:4440 [inline]
__se_sys_unlinkat fs/namei.c:4434 [inline]
__arm64_sys_unlinkat+0xcc/0xfc fs/namei.c:4434
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
irq event stamp: 424884
hardirqs last enabled at (424883): [<ffff8000083c1ba4>] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
hardirqs last enabled at (424883): [<ffff8000083c1ba4>] ktime_get_coarse_real_ts64+0x114/0x244 kernel/time/timekeeping.c:2261
hardirqs last disabled at (424884): [<ffff8000119080a8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (424224): [<ffff8000080309e0>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (424222): [<ffff8000080309ac>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
VFS: Lookup of 'file1' in minix loop6 would have caused loop
VFS: Lookup of 'file1' in minix loop6 would have caused loop


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: bec0e10ee67e Linux 6.1.160
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=12b9a59a580000

kernel config: https://syzkaller.appspot.com/x/.config?x=31ea1cecaf34f0db
dashboard link: https://syzkaller.appspot.com/bug?extid=7f28c102d91fd1e37c83
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12df95fa580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15d40522580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0c7c6a53ac77/disk-bec0e10e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/38567d4ccc5b/vmlinux-bec0e10e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5f0a7945f428/Image-bec0e10e.gz.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/6ef1e726679a/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=11d40522580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7f28c1...@syzkaller.appspotmail.com

Trying to free block not in datazone
minix_free_inode: bit 3 already cleared
minix_free_inode: bit 4 already cleared
------------[ cut here ]------------

WARNING: CPU: 1 PID: 4434 at fs/inode.c:332 drop_nlink+0xe4/0x138 fs/inode.c:332
Modules linked in:
CPU: 1 PID: 4434 Comm: syz-executor Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : drop_nlink+0xe4/0x138 fs/inode.c:332
lr : drop_nlink+0xe4/0x138 fs/inode.c:332

sp : ffff800020c47b00
x29: ffff800020c47b00 x28: ffff0000d9399bc0 x27: 1fffe0001d3e3bb9
x26: ffff800020c47b40 x25: 1ffff00004188f68 x24: dfff800000000000
x23: 1fffe0001d3f9811 x22: dfff800000000000 x21: 0000000000000000
x20: ffff0000e9fcc088 x19: ffff0000e9fcc040 x18: 0000000000000000

x17: ffff800018186000 x16: ffff8000082d4a88 x15: 0000000000000000
x14: 000000003b9aca00 x13: 0000000000000000 x12: 0000000000ff0100
x11: ff008000089ff18c x10: 0000000000000000 x9 : ffff8000089ff18c

x8 : ffff0000d9399bc0 x7 : 0000000000000000 x6 : 0000000000000032
x5 : ffff0000e9fcc0c8 x4 : ffff0000e9f900c8 x3 : ffff8000089ff160

x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
drop_nlink+0xe4/0x138 fs/inode.c:332
inode_dec_link_count include/linux/fs.h:2582 [inline]
minix_rmdir+0x164/0x1c0 fs/minix/namei.c:181
vfs_rmdir+0x304/0x438 fs/namei.c:4199
do_rmdir+0x238/0x50c fs/namei.c:4260
__do_sys_unlinkat fs/namei.c:4440 [inline]
__se_sys_unlinkat fs/namei.c:4434 [inline]
__arm64_sys_unlinkat+0xcc/0xfc fs/namei.c:4434
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

irq event stamp: 168566
hardirqs last enabled at (168565): [<ffff8000083c1ba4>] seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline]
hardirqs last enabled at (168565): [<ffff8000083c1ba4>] ktime_get_coarse_real_ts64+0x114/0x244 kernel/time/timekeeping.c:2261
hardirqs last disabled at (168566): [<ffff8000119080a8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (167434): [<ffff8000080309e0>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (167432): [<ffff8000080309ac>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19

---[ end trace 0000000000000000 ]---

VFS: Lookup of 'file1' in minix loop0 would have caused loop
VFS: Lookup of 'file1' in minix loop0 would have caused loop


---
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