general protection fault in ovl_lookup_single (2)

Status: upstream: reported C repro on 2026/06/07 16:05
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+eff0568b3b84daefa9d2@syzkaller.appspotmail.com
First crash: 49d, last: 49d
Fix bisection: failed (error log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/07/04 lts (merge base) 4fd016be1e49 C [report] lost connection to test machine
2026/07/04 upstream (ToT) 7404ce516372 C [report] lost connection to test machine
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in ovl_lookup_single 2 C 1 2d17h 168d 0/2 upstream: reported C repro on 2026/02/08 11:51
android-5-15 general protection fault in ovl_lookup_single origin:upstream 2 C 1 5d23h 67d 0/2 upstream: reported C repro on 2026/05/20 08:38
android-6-1 general protection fault in ovl_lookup_single 2 1 930d 930d 0/2 auto-obsoleted due to no activity on 2024/04/07 02:55
android-6-12 general protection fault in ovl_lookup_single origin:downstream 2 C 5 100d 185d 0/1 premoderation: reported C repro on 2026/01/22 23:16
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/06/29 06:37 14m retest repro android14-6.1 log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ovl_lookup_positive_unlocked fs/overlayfs/namei.c:209 [inline]
RIP: 0010:ovl_lookup_single+0x15e/0x9c0 fs/overlayfs/namei.c:233
Code: e8 47 1c 5e ff 49 bf 00 00 00 00 00 fc ff df e9 4b 04 00 00 44 88 6c 24 10 4d 89 f5 49 c1 ed 03 49 bf 00 00 00 00 00 fc ff df <43> 0f b6 44 3d 00 84 c0 0f 85 61 06 00 00 4d 89 f7 45 8b 36 44 89
RSP: 0018:ffffc900009a7980 EFLAGS: 00010203
RAX: 0000000000000016 RBX: ffffc900009a7bd8 RCX: 723449db75d93500
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffc900009a7a50 R08: ffff888122f195e7 R09: 1ffff110245e32bc
R10: dffffc0000000000 R11: ffffed10245e32bd R12: 1ffff92000134f7b
R13: 0000000000000002 R14: 0000000000000016 R15: dffffc0000000000
FS:  00007fc0f3e096c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0f3dc6ff8 CR3: 000000012f50b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ovl_lookup_layer+0x355/0x420 fs/overlayfs/namei.c:320
 ovl_lookup+0x728/0x1980 fs/overlayfs/namei.c:923
 lookup_one_qstr_excl+0x125/0x270 fs/namei.c:1612
 filename_create+0x235/0x470 fs/namei.c:3884
 do_mkdirat+0x5c/0x4c0 fs/namei.c:4128
 __do_sys_mkdirat fs/namei.c:4153 [inline]
 __se_sys_mkdirat fs/namei.c:4151 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4151
 x64_sys_call+0x73d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc0f2f9ce59
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:00007fc0f3e09028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fc0f3215fa0 RCX: 00007fc0f2f9ce59
RDX: 0000000000000000 RSI: 0000200000002000 RDI: ffffffffffffff9c
RBP: 00007fc0f3032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc0f3216038 R14: 00007fc0f3215fa0 R15: 00007fff06d384a8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ovl_lookup_positive_unlocked fs/overlayfs/namei.c:209 [inline]
RIP: 0010:ovl_lookup_single+0x15e/0x9c0 fs/overlayfs/namei.c:233
Code: e8 47 1c 5e ff 49 bf 00 00 00 00 00 fc ff df e9 4b 04 00 00 44 88 6c 24 10 4d 89 f5 49 c1 ed 03 49 bf 00 00 00 00 00 fc ff df <43> 0f b6 44 3d 00 84 c0 0f 85 61 06 00 00 4d 89 f7 45 8b 36 44 89
RSP: 0018:ffffc900009a7980 EFLAGS: 00010203
RAX: 0000000000000016 RBX: ffffc900009a7bd8 RCX: 723449db75d93500
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffc900009a7a50 R08: ffff888122f195e7 R09: 1ffff110245e32bc
R10: dffffc0000000000 R11: ffffed10245e32bd R12: 1ffff92000134f7b
R13: 0000000000000002 R14: 0000000000000016 R15: dffffc0000000000
FS:  00007fc0f3e096c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0f3dc6ff8 CR3: 000000012f50b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 47 1c 5e ff       	call   0xff5e1c4c
   5:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
   c:	fc ff df
   f:	e9 4b 04 00 00       	jmp    0x45f
  14:	44 88 6c 24 10       	mov    %r13b,0x10(%rsp)
  19:	4d 89 f5             	mov    %r14,%r13
  1c:	49 c1 ed 03          	shr    $0x3,%r13
  20:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  27:	fc ff df
* 2a:	43 0f b6 44 3d 00    	movzbl 0x0(%r13,%r15,1),%eax <-- trapping instruction
  30:	84 c0                	test   %al,%al
  32:	0f 85 61 06 00 00    	jne    0x699
  38:	4d 89 f7             	mov    %r14,%r15
  3b:	45 8b 36             	mov    (%r14),%r14d
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/07 16:04 android14-6.1 d73749230104 cc095639 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in ovl_lookup_single
* Struck through repros no longer work on HEAD.