[moderation] [hfs?] general protection fault in hfsplus_cat_write_inode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c22e26bd0906 Merge tag 'landlock-7.0-rc1' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11d32722580000
kernel config: https://syzkaller.appspot.com/x/.config?x=6428d17febdfb14e
dashboard link: https://syzkaller.appspot.com/bug?extid=c7efb37aa1355d5e631b
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [fran...@vivo.com glau...@physik.fu-berlin.de linux-...@vger.kernel.org linux-...@vger.kernel.org sl...@dubeyko.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d68a15a17667/disk-c22e26bd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b8799409c3a5/vmlinux-c22e26bd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2c41c867ca47/bzImage-c22e26bd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c7efb3...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 UID: 0 PID: 8473 Comm: syz.7.54 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:hfsplus_cat_write_inode+0xbe/0x8f0 fs/hfsplus/inode.c:637
Code: f3 f3 4a 89 44 33 51 4a 89 44 33 59 66 42 c7 44 33 61 f3 f3 42 c6 44 33 63 f3 e8 4d 43 26 ff 4d 8d 7d 28 4c 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 ff e8 a3 5c 8b ff 41 be 98 07 00 00 4d
RSP: 0018:ffffc90005fe7880 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 1ffff92000bfcf14 RCX: 0000000000080000
RDX: ffffc9001497b000 RSI: 0000000000000e37 RDI: 0000000000000e38
RBP: ffffc90005fe7c10 R08: 0000000000000004 R09: 0000000000000004
R10: fffff52000bfcf24 R11: fffffbfff1e9250f R12: 1ffff92000bfcf8c
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000028
FS: 00007ffa374b56c0(0000) GS:ffff888126695000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa37493ff8 CR3: 00000000318c4000 CR4: 00000000003526f0
Call Trace:
<TASK>
hfsplus_unlink+0x57a/0x930 fs/hfsplus/dir.c:435
vfs_unlink+0x272/0x6d0 fs/namei.c:5470
filename_unlinkat+0x3d3/0x610 fs/namei.c:5540
__do_sys_unlinkat fs/namei.c:5569 [inline]
__se_sys_unlinkat+0x83/0x1a0 fs/namei.c:5561
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa3927bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffa374b5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007ffa394f6090 RCX: 00007ffa3927bf79
RDX: 0000000000000000 RSI: 0000200000000380 RDI: ffffffffffffff9c
RBP: 00007ffa393127e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffa394f6128 R14: 00007ffa394f6090 R15: 00007fff4cf8e5b8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfsplus_cat_write_inode+0xbe/0x8f0 fs/hfsplus/inode.c:637
Code: f3 f3 4a 89 44 33 51 4a 89 44 33 59 66 42 c7 44 33 61 f3 f3 42 c6 44 33 63 f3 e8 4d 43 26 ff 4d 8d 7d 28 4c 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 ff e8 a3 5c 8b ff 41 be 98 07 00 00 4d
RSP: 0018:ffffc90005fe7880 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 1ffff92000bfcf14 RCX: 0000000000080000
RDX: ffffc9001497b000 RSI: 0000000000000e37 RDI: 0000000000000e38
RBP: ffffc90005fe7c10 R08: 0000000000000004 R09: 0000000000000004
R10: fffff52000bfcf24 R11: fffffbfff1e9250f R12: 1ffff92000bfcf8c
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000028
FS: 00007ffa374b56c0(0000) GS:ffff888126695000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa37493ff8 CR3: 00000000318c4000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: f3 f3 4a 89 44 33 51 repz xrelease mov %rax,0x51(%rbx,%r14,1)
7: 4a 89 44 33 59 mov %rax,0x59(%rbx,%r14,1)
c: 66 42 c7 44 33 61 f3 movw $0xf3f3,0x61(%rbx,%r14,1)
13: f3
14: 42 c6 44 33 63 f3 movb $0xf3,0x63(%rbx,%r14,1)
1a: e8 4d 43 26 ff call 0xff26436c
1f: 4d 8d 7d 28 lea 0x28(%r13),%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ff mov %r15,%rdi
34: e8 a3 5c 8b ff call 0xff8b5cdc
39: 41 be 98 07 00 00 mov $0x798,%r14d
3f: 4d rex.WRB


---
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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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

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