syzbot


general protection fault in hfsplus_cat_write_inode

Status: moderation: reported on 2026/02/17 19:48
Subsystems: hfs
[Documentation on labels]
Reported-by: syzbot+c7efb37aa1355d5e631b@syzkaller.appspotmail.com
First crash: 2d16h, last: 2d16h

Sample crash report:
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

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/16 12:52 upstream c22e26bd0906 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in hfsplus_cat_write_inode
* Struck through repros no longer work on HEAD.