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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 54e82e93ca93 Merge tag 'core_urgent_for_v6.19_rc4' of git:..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12de7dfc580000
kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=63c5597a683630268757
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-54e82e93.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f3befb5f53a4/vmlinux-54e82e93.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92820ca1dbd8/bzImage-54e82e93.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+63c559...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 1024
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 UID: 0 PID: 5337 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__hfsplus_brec_find+0xad/0x480 fs/hfsplus/bfind.c:113
Code: 74 24 28 4d 85 f6 0f 84 db 03 00 00 66 c7 44 24 60 00 00 c7 84 24 80 00 00 00 00 00 00 00 4d 8d 74 24 18 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 d6 02 00 00 48 89 5c 24 30 41 0f b7 06
RSP: 0000:ffffc9000dba76e0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 1ffff92001b74ee4 RCX: ffff888035fb24c0
RDX: 0000000000000000 RSI: ffffc9000dba79e0 RDI: fffffffffffffffb
RBP: ffffc9000dba77d0 R08: 0000030000000600 R09: 0000030000000600
R10: dffffc0000000000 R11: ffffed100822cc01 R12: fffffffffffffffb
R13: dffffc0000000000 R14: 0000000000000013 R15: ffffc9000dba79e0
FS: 00007fe9a62126c0(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffbfa97fc0 CR3: 0000000041be5000 CR4: 0000000000352ef0
Call Trace:
<TASK>
hfsplus_brec_insert+0x8c6/0xd70 fs/hfsplus/brec.c:160
hfsplus_create_cat+0x9a9/0x10d0 fs/hfsplus/catalog.c:308
hfsplus_mknod+0x16a/0x290 fs/hfsplus/dir.c:494
vfs_create+0x3aa/0x400 fs/namei.c:4132
do_mknodat+0x3ea/0x610 fs/namei.c:5039
__do_sys_mknod fs/namei.c:5076 [inline]
__se_sys_mknod fs/namei.c:5074 [inline]
__x64_sys_mknod+0x8c/0xa0 fs/namei.c:5074
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe9a538f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe9a6212038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007fe9a55e5fa0 RCX: 00007fe9a538f7c9
RDX: 0000000000000701 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fe9a5413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe9a55e6038 R14: 00007fe9a55e5fa0 R15: 00007fffbfa98798
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__hfsplus_brec_find+0xad/0x480 fs/hfsplus/bfind.c:113
Code: 74 24 28 4d 85 f6 0f 84 db 03 00 00 66 c7 44 24 60 00 00 c7 84 24 80 00 00 00 00 00 00 00 4d 8d 74 24 18 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 d6 02 00 00 48 89 5c 24 30 41 0f b7 06
RSP: 0000:ffffc9000dba76e0 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 1ffff92001b74ee4 RCX: ffff888035fb24c0
RDX: 0000000000000000 RSI: ffffc9000dba79e0 RDI: fffffffffffffffb
RBP: ffffc9000dba77d0 R08: 0000030000000600 R09: 0000030000000600
R10: dffffc0000000000 R11: ffffed100822cc01 R12: fffffffffffffffb
R13: dffffc0000000000 R14: 0000000000000013 R15: ffffc9000dba79e0
FS: 00007fe9a62126c0(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffbfa97fc0 CR3: 0000000041be5000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 74 24 je 0x26
2: 28 4d 85 sub %cl,-0x7b(%rbp)
5: f6 0f 84 testb $0x84,(%rdi)
8: db 03 fildl (%rbx)
a: 00 00 add %al,(%rax)
c: 66 c7 44 24 60 00 00 movw $0x0,0x60(%rsp)
13: c7 84 24 80 00 00 00 movl $0x0,0x80(%rsp)
1a: 00 00 00 00
1e: 4d 8d 74 24 18 lea 0x18(%r12),%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 d6 02 00 00 jne 0x30d
37: 48 89 5c 24 30 mov %rbx,0x30(%rsp)
3c: 41 0f b7 06 movzwl (%r14),%eax


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