[v5.15] kernel BUG in jfs_unlink

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3dea0e7f549e Linux 5.15.186
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=144da982580000
kernel config: https://syzkaller.appspot.com/x/.config?x=68f6f35276e57732
dashboard link: https://syzkaller.appspot.com/bug?extid=68a4af373418d75ac55f
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/90580e8155e1/disk-3dea0e7f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fa25a3db336a/vmlinux-3dea0e7f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b05b2d29242/Image-3dea0e7f.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+68a4af...@syzkaller.appspotmail.com

BUG at fs/jfs/namei.c:513 assert(ip->i_nlink)
------------[ cut here ]------------
kernel BUG at fs/jfs/namei.c:513!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4036 Comm: syz-executor Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : jfs_unlink+0x8c8/0x8f4 fs/jfs/namei.c:513
lr : jfs_unlink+0x8c8/0x8f4 fs/jfs/namei.c:513
sp : ffff80001f137a80
x29: ffff80001f137b70 x28: dfff800000000000 x27: ffff700003e26f58
x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000000
x23: 1ffff000028d83ac x22: ffff0000e98538e0 x21: ffff0000e9853bb0
x20: ffff0000e9855798 x19: ffff80001f137ac0 x18: 0000000000000002
x17: ffff800016cf2000 x16: ffff8000111b2714 x15: ffff8000167d2500
x14: ffff0000dd0d2540 x13: 1ffff0000282c06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : dc292c378cac2100
x8 : dc292c378cac2100 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff80000a7343e4
x2 : ffff0001a10e9d50 x1 : 0000000100000000 x0 : 000000000000002d
Call trace:
jfs_unlink+0x8c8/0x8f4 fs/jfs/namei.c:513
vfs_unlink+0x2e0/0x4f4 fs/namei.c:4280
do_unlinkat+0x31c/0x600 fs/namei.c:4348
__do_sys_unlinkat fs/namei.c:4391 [inline]
__se_sys_unlinkat fs/namei.c:4384 [inline]
__arm64_sys_unlinkat+0xe0/0xfc fs/namei.c:4384
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 9003f6a3 91028063 52804022 95e5a93a (d4210000)
---[ end trace afb5e9ebb8f432eb ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.