[v6.1] WARNING in inc_nlink (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4aa6747d9352 Linux 6.1.69
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=141970cee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1e9066810307299
dashboard link: https://syzkaller.appspot.com/bug?extid=9e9d439464190b89a70c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/209330361447/disk-4aa6747d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/48aa2c86988d/vmlinux-4aa6747d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/84320338eba6/bzImage-4aa6747d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e9d43...@syzkaller.appspotmail.com

REISERFS (device loop2): Created .reiserfs_priv - reserved for xattr storage.
REISERFS error (device loop2): vs-7000 search_by_entry_key: search_by_key returned item position == 0
REISERFS (device loop2): Remounting filesystem read-only
REISERFS warning (device loop2): PAP-5610 reiserfs_cut_from_item: item [1 0 2342656(0) DIR] not found
------------[ cut here ]------------
WARNING: CPU: 0 PID: 18291 at fs/inode.c:387 inc_nlink+0x120/0x130
Modules linked in:
CPU: 0 PID: 18291 Comm: syz-executor.2 Not tainted 6.1.69-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:inc_nlink+0x120/0x130 fs/inode.c:387
Code: ea ff e9 37 ff ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 49 ff ff ff 4c 89 ef e8 3a 25 ea ff e9 3c ff ff ff e8 50 c4 92 ff <0f> 0b eb 80 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 53 48
RSP: 0018:ffffc90004997aa8 EFLAGS: 00010283
RAX: ffffffff81f7c9c0 RBX: 1ffff11014816f23 RCX: 0000000000040000
RDX: ffffc9000aafa000 RSI: 000000000000c3ad RDI: 000000000000c3ae
RBP: 0000000000000000 R08: ffffffff81f7c93a R09: fffffbfff2091e6b
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880a40b7918 R14: ffff8880a40b78d0 R15: 0000000000000007
FS: 00007f37db1756c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33625000 CR3: 00000000a4ac5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
reiserfs_unlink+0x69d/0x790 fs/reiserfs/namei.c:1072
vfs_unlink+0x359/0x5f0 fs/namei.c:4253
do_unlinkat+0x49f/0x820 fs/namei.c:4321
__do_sys_unlink fs/namei.c:4369 [inline]
__se_sys_unlink fs/namei.c:4367 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4367
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f37da47cce9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f37db1750c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f37da59bf80 RCX: 00007f37da47cce9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00007f37db175120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 000000000000000b R14: 00007f37da59bf80 R15: 00007ffc6f0d0f08
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 4aa6747d9352 Linux 6.1.69
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=13c6e49ae80000

kernel config: https://syzkaller.appspot.com/x/.config?x=e1e9066810307299
dashboard link: https://syzkaller.appspot.com/bug?extid=9e9d439464190b89a70c
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=172fac65e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17305855e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/209330361447/disk-4aa6747d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/48aa2c86988d/vmlinux-4aa6747d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/84320338eba6/bzImage-4aa6747d.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/46876042aa58/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e9d43...@syzkaller.appspotmail.com

REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
REISERFS error (device loop0): vs-7000 search_by_entry_key: search_by_key returned item position == 0
REISERFS (device loop0): Remounting filesystem read-only
REISERFS warning (device loop0): PAP-5610 reiserfs_cut_from_item: item [1 0 2342656(0) DIR] not found
------------[ cut here ]------------
WARNING: CPU: 0 PID: 3542 at fs/inode.c:387 inc_nlink+0x120/0x130
Modules linked in:
CPU: 0 PID: 3542 Comm: syz-executor250 Not tainted 6.1.69-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:inc_nlink+0x120/0x130 fs/inode.c:387
Code: ea ff e9 37 ff ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 49 ff ff ff 4c 89 ef e8 3a 25 ea ff e9 3c ff ff ff e8 50 c4 92 ff <0f> 0b eb 80 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 53 48

RSP: 0018:ffffc900039afaa8 EFLAGS: 00010293
RAX: ffffffff81f7c9c0 RBX: 1ffff1100e40a03b RCX: ffff88802995bb80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81f7c93a R09: fffffbfff2091e5e

R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000

R13: ffff8880720501d8 R14: ffff888072050190 R15: 0000000000000000
FS: 0000555556a2b380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000

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

CR2: 00007fee28b95ed8 CR3: 000000007966f000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
reiserfs_unlink+0x69d/0x790 fs/reiserfs/namei.c:1072
vfs_unlink+0x359/0x5f0 fs/namei.c:4253
do_unlinkat+0x49f/0x820 fs/namei.c:4321
__do_sys_unlink fs/namei.c:4369 [inline]
__se_sys_unlink fs/namei.c:4367 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4367
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd

RIP: 0033:0x7f3cb49c81b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 1c 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd20ec67c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3cb49c81b9
RDX: 00007f3cb49c7370 RSI: 00007ffd20ec68b0 RDI: 0000000020000040
RBP: 00007ffd20ec68d0 R08: 00007ffd20ec6567 R09: 0000555556a2bfc0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000000c
R13: 0000000000050012 R14: 0000000000000003 R15: 00007ffd20ec68b0
</TASK>


---
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