[syzbot] [hfs?] general protection fault in __hfsplus_setxattr

[syzbot <syzbot+bc70a12e438dadba4fb4@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    d60bc1401583 Merge tag 'pwrseq-updates-for-v7.1-rc1' of gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1605b036580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=85bd86f990609a1
dashboard link: https://syzkaller.appspot.com/bug?extid=bc70a12e438dadba4fb4
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=143efeba580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1769e8ce580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c962a506ef36/disk-d60bc140.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8590a2666b51/vmlinux-d60bc140.xz
kernel image: https://storage.googleapis.com/syzbot-assets/75aa1f8fc11f/bzImage-d60bc140.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e3cd44efac38/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bc70a12e438dadba4fb4@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 1024
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 UID: 0 PID: 5977 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:hfsplus_create_attributes_file fs/hfsplus/xattr.c:320 [inline]
RIP: 0010:__hfsplus_setxattr+0x1c68/0x2860 fs/hfsplus/xattr.c:432
Code: 8b 36 49 83 c6 30 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 46 f8 80 ff 4d 8b 36 49 83 c6 08 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 29 f8 80 ff 4d 8b 36 49 8d 7e 90
RSP: 0018:ffffc90002f37420 EFLAGS: 00010212
RAX: 0000000000000001 RBX: fffff520005e6ea4 RCX: ffff88802f39db80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002f378f8 R08: ffffea00017e23f7 R09: 1ffffd40002fc47e
R10: dffffc0000000000 R11: fffff940002fc47f R12: dffffc0000000000
R13: ffff88802bb42a30 R14: 0000000000000008 R15: ffff88802bb43740
FS:  000055555c219500(0000) GS:ffff88812554b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f407bb7b000 CR3: 0000000077cf5000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 hfsplus_setxattr+0x124/0x340 fs/hfsplus/xattr.c:555
 hfsplus_trusted_setxattr+0x40/0x60 fs/hfsplus/xattr_trusted.c:30
 __vfs_setxattr+0x43c/0x480 fs/xattr.c:218
 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:252
 vfs_setxattr+0x163/0x360 fs/xattr.c:339
 do_setxattr fs/xattr.c:654 [inline]
 filename_setxattr+0x296/0x630 fs/xattr.c:682
 path_setxattrat+0x3eb/0x440 fs/xattr.c:726
 __do_sys_setxattr fs/xattr.c:760 [inline]
 __se_sys_setxattr fs/xattr.c:756 [inline]
 __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:756
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcafdf9c819
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:00007ffd135f08f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007fcafe215fa0 RCX: 00007fcafdf9c819
RDX: 0000200000001400 RSI: 00002000000001c0 RDI: 0000200000000380
RBP: 00007fcafe032c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcafe215fac R14: 00007fcafe215fa0 R15: 00007fcafe215fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hfsplus_create_attributes_file fs/hfsplus/xattr.c:320 [inline]
RIP: 0010:__hfsplus_setxattr+0x1c68/0x2860 fs/hfsplus/xattr.c:432
Code: 8b 36 49 83 c6 30 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 46 f8 80 ff 4d 8b 36 49 83 c6 08 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 29 f8 80 ff 4d 8b 36 49 8d 7e 90
RSP: 0018:ffffc90002f37420 EFLAGS: 00010212
RAX: 0000000000000001 RBX: fffff520005e6ea4 RCX: ffff88802f39db80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002f378f8 R08: ffffea00017e23f7 R09: 1ffffd40002fc47e
R10: dffffc0000000000 R11: fffff940002fc47f R12: dffffc0000000000
R13: ffff88802bb42a30 R14: 0000000000000008 R15: ffff88802bb43740
FS:  000055555c219500(0000) GS:ffff88812544b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562d49fd15e0 CR3: 0000000077cf5000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	8b 36                	mov    (%rsi),%esi
   2:	49 83 c6 30          	add    $0x30,%r14
   6:	4c 89 f0             	mov    %r14,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
  12:	74 08                	je     0x1c
  14:	4c 89 f7             	mov    %r14,%rdi
  17:	e8 46 f8 80 ff       	call   0xff80f862
  1c:	4d 8b 36             	mov    (%r14),%r14
  1f:	49 83 c6 08          	add    $0x8,%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 29 f8 80 ff       	call   0xff80f862
  39:	4d 8b 36             	mov    (%r14),%r14
  3c:	49 8d 7e 90          	lea    -0x70(%r14),%rdi


---
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