BUG: unable to handle kernel paging request in __hfsplus_brec_find

Status: moderation: reported on 2026/09/13 20:22
Subsystems: hfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+f957cf00261d1c41fafd@syzkaller.appspotmail.com
First crash: 4d01h, last: 4d01h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
9400239e assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ BUG: unable to handle kernel paging request in __hfsplus_brec_find 2026/09/11 00:29 2026/09/11 00:29 2026/09/11 01:09 1fe56c0a
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in __hfsplus_brec_find hfs 2 1 240d 236d 0/29 auto-obsoleted due to no activity on 2026/04/16 13:28

Sample crash report:
BUG: unable to handle page fault for address: fffffffffffffffb
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD eb4b067 P4D eb4b067 PUD eb4d067 PMD 0 
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5318 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 04/01/2014
RIP: 0010:hfs_bnode_num_recs_invalid fs/hfsplus/hfsplus_fs.h:605 [inline]
RIP: 0010:__hfsplus_brec_find+0xe0/0x850 fs/hfsplus/bfind.c:114
Code: e8 c5 6f 7f ff 4d 85 ff 74 67 48 89 5c 24 38 4c 89 f8 48 c1 e8 03 48 89 44 24 10 42 80 3c 20 00 74 08 4c 89 ff e8 d0 6c 7f ff <49> 8b 1f 48 85 db 74 4b 4c 89 6c 24 28 48 83 c3 38 48 89 d8 48 c1
RSP: 0018:ffffc9000e93f480 EFLAGS: 00010246
RAX: 1fffffffffffffff RBX: ffffc9000e93f820 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000ff RDI: ffffc9000e93f834
RBP: ffffc9000e93f570 R08: ffffc9000e93f833 R09: 0000000000000000
R10: ffffc9000e93f820 R11: fffff52001d27f07 R12: dffffc0000000000
R13: ffffc9000e93f800 R14: 1ffff92001d27e98 R15: fffffffffffffffb
FS:  00007f61883236c0(0000) GS:ffff88808c2ca000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffb CR3: 000000001296f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 hfsplus_brec_insert+0x90e/0xde0 fs/hfsplus/brec.c:170
 hfsplus_rename_cat+0x5b2/0x1070 fs/hfsplus/catalog.c:481
 hfsplus_rename+0x145/0x280 fs/hfsplus/dir.c:596
 vfs_rename+0xbd9/0xef0 fs/namei.c:6208
 filename_renameat2+0x533/0x9a0 fs/namei.c:6326
 __do_sys_rename fs/namei.c:6370 [inline]
 __se_sys_rename+0x55/0x2c0 fs/namei.c:6366
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f618739e159
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:00007f6188322fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f6187626090 RCX: 00007f618739e159
RDX: 0000000000000000 RSI: 0000200000000f40 RDI: 0000200000000600
RBP: 00007f618743503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6187626128 R14: 00007f6187626090 R15: 00007ffea84da5d8
 </TASK>
Modules linked in:
CR2: fffffffffffffffb
---[ end trace 0000000000000000 ]---
RIP: 0010:hfs_bnode_num_recs_invalid fs/hfsplus/hfsplus_fs.h:605 [inline]
RIP: 0010:__hfsplus_brec_find+0xe0/0x850 fs/hfsplus/bfind.c:114
Code: e8 c5 6f 7f ff 4d 85 ff 74 67 48 89 5c 24 38 4c 89 f8 48 c1 e8 03 48 89 44 24 10 42 80 3c 20 00 74 08 4c 89 ff e8 d0 6c 7f ff <49> 8b 1f 48 85 db 74 4b 4c 89 6c 24 28 48 83 c3 38 48 89 d8 48 c1
RSP: 0018:ffffc9000e93f480 EFLAGS: 00010246
RAX: 1fffffffffffffff RBX: ffffc9000e93f820 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000ff RDI: ffffc9000e93f834
RBP: ffffc9000e93f570 R08: ffffc9000e93f833 R09: 0000000000000000
R10: ffffc9000e93f820 R11: fffff52001d27f07 R12: dffffc0000000000
R13: ffffc9000e93f800 R14: 1ffff92001d27e98 R15: fffffffffffffffb
FS:  00007f61883236c0(0000) GS:ffff88808c2ca000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffb CR3: 000000001296f000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	e8 c5 6f 7f ff       	call   0xff7f6fca
   5:	4d 85 ff             	test   %r15,%r15
   8:	74 67                	je     0x71
   a:	48 89 5c 24 38       	mov    %rbx,0x38(%rsp)
   f:	4c 89 f8             	mov    %r15,%rax
  12:	48 c1 e8 03          	shr    $0x3,%rax
  16:	48 89 44 24 10       	mov    %rax,0x10(%rsp)
  1b:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
  20:	74 08                	je     0x2a
  22:	4c 89 ff             	mov    %r15,%rdi
  25:	e8 d0 6c 7f ff       	call   0xff7f6cfa
* 2a:	49 8b 1f             	mov    (%r15),%rbx <-- trapping instruction
  2d:	48 85 db             	test   %rbx,%rbx
  30:	74 4b                	je     0x7d
  32:	4c 89 6c 24 28       	mov    %r13,0x28(%rsp)
  37:	48 83 c3 38          	add    $0x38,%rbx
  3b:	48 89 d8             	mov    %rbx,%rax
  3e:	48                   	rex.W
  3f:	c1                   	.byte 0xc1

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/09 20:16 upstream 893e11787f78 edec9137 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root BUG: unable to handle kernel paging request in __hfsplus_brec_find
* Struck through repros no longer work on HEAD.