syzbot


general protection fault in do_unlinkat

Status: premoderation: reported C repro on 2025/07/15 16:32
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+182816dea312c849adc5@syzkaller.appspotmail.com
First crash: 210d, last: 2d01h
Bug presence (3)
Date Name Commit Repro Result
2025/07/15 android16-6.12 (ToT) a11268a7e257 C [report] general protection fault in do_unlinkat
2025/07/15 lts (merge base) e0e2f7824338 C Didn't crash
2025/07/15 upstream (ToT) 155a3c003e55 C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in do_unlinkat 2 C done 50 13d 955d 0/2 upstream: reported C repro on 2023/07/01 21:31
android-5-15 general protection fault in do_unlinkat origin:downstream 2 C done 15 5d01h 955d 0/2 upstream: reported C repro on 2023/07/01 22:19
android-6-1 general protection fault in do_unlinkat origin:downstream 2 C done 10 8d19h 955d 0/2 upstream: reported C repro on 2023/07/01 22:19
Last patch testing requests (8)
Created Duration User Patch Repo Result
2026/01/05 04:26 4m retest repro android16-6.12 error
2025/12/18 20:00 8m retest repro android16-6.12 error
2025/12/04 03:11 4m retest repro android16-6.12 error
2025/10/27 02:23 4m retest repro android16-6.12 error
2025/10/09 16:14 7m retest repro android16-6.12 report log
2025/09/24 23:40 30m retest repro android16-6.12 report log
2025/08/17 01:31 11m retest repro android16-6.12 report log
2025/07/30 13:59 10m retest repro android16-6.12 report log

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 UID: 0 PID: 382 Comm: syz.2.17 Not tainted syzkaller #0 e538f3f6a543b135812147031d083fd1f2699041
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:419 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:465 [inline]
RIP: 0010:do_unlinkat+0x29c/0x5a0 fs/namei.c:4534
Code: 00 00 20 00 89 de e8 43 9f 99 ff 45 31 f6 81 fb 00 00 20 00 41 0f 95 c6 41 83 c6 eb 31 db e9 f4 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 04 02 00 00 41 8b 1f be 00 00 70 00 21
RSP: 0018:ffffc90000e2fde0 EFLAGS: 00010203
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888116139300 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000e2fee0 R08: ffff8881f6e50bc7 R09: 1ffff1103edca178
R10: dffffc0000000000 R11: ffffed103edca179 R12: ffff88811612a200
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000016
FS:  00007f7a273146c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000008fe0 CR3: 0000000116054000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __do_sys_unlinkat fs/namei.c:4584 [inline]
 __se_sys_unlinkat fs/namei.c:4577 [inline]
 __x64_sys_unlinkat+0xda/0xf0 fs/namei.c:4577
 x64_sys_call+0x2974/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:264
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f7a2639aeb9
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:00007f7a27314028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f7a26615fa0 RCX: 00007f7a2639aeb9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f7a26408c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a26616038 R14: 00007f7a26615fa0 R15: 00007ffd1f07b6d8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__d_entry_type include/linux/dcache.h:414 [inline]
RIP: 0010:d_is_miss include/linux/dcache.h:419 [inline]
RIP: 0010:d_is_negative include/linux/dcache.h:465 [inline]
RIP: 0010:do_unlinkat+0x29c/0x5a0 fs/namei.c:4534
Code: 00 00 20 00 89 de e8 43 9f 99 ff 45 31 f6 81 fb 00 00 20 00 41 0f 95 c6 41 83 c6 eb 31 db e9 f4 00 00 00 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 04 02 00 00 41 8b 1f be 00 00 70 00 21
RSP: 0018:ffffc90000e2fde0 EFLAGS: 00010203
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888116139300 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000e2fee0 R08: ffff8881f6e50bc7 R09: 1ffff1103edca178
R10: dffffc0000000000 R11: ffffed103edca179 R12: ffff88811612a200
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000016
FS:  00007f7a273146c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000008fe0 CR3: 0000000116054000 CR4: 00000000003526b0
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	20 00                	and    %al,(%rax)
   4:	89 de                	mov    %ebx,%esi
   6:	e8 43 9f 99 ff       	call   0xff999f4e
   b:	45 31 f6             	xor    %r14d,%r14d
   e:	81 fb 00 00 20 00    	cmp    $0x200000,%ebx
  14:	41 0f 95 c6          	setne  %r14b
  18:	41 83 c6 eb          	add    $0xffffffeb,%r14d
  1c:	31 db                	xor    %ebx,%ebx
  1e:	e9 f4 00 00 00       	jmp    0x117
  23:	4c 89 f8             	mov    %r15,%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 04 02 00 00    	jne    0x23b
  37:	41 8b 1f             	mov    (%r15),%ebx
  3a:	be 00 00 70 00       	mov    $0x700000,%esi
  3f:	21                   	.byte 0x21

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/09 08:12 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
2025/08/02 17:08 android16-6.12 bf0fb8bb181b 7368264b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
2025/07/15 18:08 android16-6.12 2bd1f3631412 03fcfc4b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
2025/07/15 17:21 android16-6.12 2bd1f3631412 03fcfc4b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
2026/02/09 07:32 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
2025/08/23 17:15 android16-6.12 c9198633ac9e bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
2025/07/15 16:31 android16-6.12 2bd1f3631412 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in do_unlinkat
* Struck through repros no longer work on HEAD.