[v5.15] WARNING in minix_rmdir (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=170cb4f0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f3b1215b3cf4119f
dashboard link: https://syzkaller.appspot.com/bug?extid=0b465d51937d865b9211
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: https://storage.googleapis.com/syzbot-assets/fa511d2a8893/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f14b6c77bbb9/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/388987ba15c6/bzImage-c7964837.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0b465d...@syzkaller.appspotmail.com

minix_free_inode: bit 5 already cleared
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4183 at fs/inode.c:332 drop_nlink+0xbb/0x100 fs/inode.c:332
Modules linked in:
CPU: 1 PID: 4183 Comm: syz-executor Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:drop_nlink+0xbb/0x100 fs/inode.c:332
Code: 48 8b 1b 48 8d bb c8 07 00 00 be 08 00 00 00 e8 0b 12 ef ff f0 48 ff 83 c8 07 00 00 5b 41 5c 41 5e 41 5f 5d c3 e8 15 ad aa ff <0f> 0b eb 88 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 62 ff ff ff 4c
RSP: 0018:ffffc90002e4fcd0 EFLAGS: 00010293
RAX: ffffffff81cd170b RBX: ffff888061f79030 RCX: ffff88807a621dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad2dd6
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: 1ffff1100c3ef20f
R13: ffffc90002e4fd40 R14: ffff888061f79078 R15: dffffc0000000000
FS: 000055555d535500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f649d4eb000 CR3: 00000000629ef000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2503 [inline]
minix_rmdir+0x176/0x1d0 fs/minix/namei.c:181
vfs_rmdir+0x1b2/0x430 fs/namei.c:4149
do_rmdir+0x295/0x710 fs/namei.c:4210
__do_sys_unlinkat fs/namei.c:4390 [inline]
__se_sys_unlinkat fs/namei.c:4384 [inline]
__x64_sys_unlinkat+0xc0/0xe0 fs/namei.c:4384
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1e6b100f87
Code: 73 01 c3 48 c7 c1 a8 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 07 01 00 00 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:00007fff548131a8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f1e6b100f87
RDX: 0000000000000200 RSI: 00007fff54814350 RDI: 00000000ffffff9c
RBP: 00007f1e6b183b55 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000207 R12: 00007fff54814350
R13: 00007f1e6b183b55 R14: 0000000000015348 R15: 00007fff54816510
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=10d7c034580000

kernel config: https://syzkaller.appspot.com/x/.config?x=f3b1215b3cf4119f
dashboard link: https://syzkaller.appspot.com/bug?extid=0b465d51937d865b9211
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1654c782580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14d7c034580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fa511d2a8893/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f14b6c77bbb9/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/388987ba15c6/bzImage-c7964837.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/8184671c2831/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1757c034580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0b465d...@syzkaller.appspotmail.com

minix_free_inode: bit 5 already cleared
------------[ cut here ]------------

WARNING: CPU: 0 PID: 4289 at fs/inode.c:332 drop_nlink+0xbb/0x100 fs/inode.c:332
Modules linked in:
CPU: 0 PID: 4289 Comm: syz-executor Not tainted 5.15.189-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:drop_nlink+0xbb/0x100 fs/inode.c:332
Code: 48 8b 1b 48 8d bb c8 07 00 00 be 08 00 00 00 e8 0b 12 ef ff f0 48 ff 83 c8 07 00 00 5b 41 5c 41 5e 41 5f 5d c3 e8 15 ad aa ff <0f> 0b eb 88 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 62 ff ff ff 4c

RSP: 0018:ffffc900030cfcd0 EFLAGS: 00010293
RAX: ffffffff81cd170b RBX: ffff888068c48590 RCX: ffff888020641dc0

RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad2dd6

R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: 1ffff1100d1890bb
R13: ffffc900030cfd40 R14: ffff888068c485d8 R15: dffffc0000000000
FS: 00005555696fb500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 000000c007d5d000 CR3: 00000000216ac000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2503 [inline]
minix_rmdir+0x176/0x1d0 fs/minix/namei.c:181
vfs_rmdir+0x1b2/0x430 fs/namei.c:4149
do_rmdir+0x295/0x710 fs/namei.c:4210
__do_sys_unlinkat fs/namei.c:4390 [inline]
__se_sys_unlinkat fs/namei.c:4384 [inline]
__x64_sys_unlinkat+0xc0/0xe0 fs/namei.c:4384
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

RIP: 0033:0x7f2675747f87

Code: 73 01 c3 48 c7 c1 a8 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 07 01 00 00 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:00007ffee6e250b8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f2675747f87
RDX: 0000000000000200 RSI: 00007ffee6e26260 RDI: 00000000ffffff9c
RBP: 00007f26757cab55 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffee6e26260
R13: 00007f26757cab55 R14: 0000000000014be6 R15: 00007ffee6e28420
</TASK>


---
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