syzbot


general protection fault in do_unlinkat

Status: upstream: reported C repro on 2023/07/01 22:19
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+7463da04bf95c393a7b7@syzkaller.appspotmail.com
First crash: 744d, last: 3d08h
Cause bisection: introduced by (bisect log) :
commit 57f3ff9648991998d008ecf32f2f9e78a08bfb8b
Author: Daniel Rosenberg <drosen@google.com>
Date: Thu Dec 2 21:50:02 2021 +0000

  ANDROID: fuse-bpf v1.1

Crash: general protection fault in do_unlinkat (log)
Repro: C syz .config
  
Bug presence (3)
Date Name Commit Repro Result
2023/07/05 android14-6.1 (ToT) f63b2625af7c C [report] general protection fault in do_unlinkat
2023/07/05 lts (merge base) b1644a0031cf C Didn't crash
2023/07/05 upstream (ToT) d528014517f2 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 41 23d 744d 0/2 upstream: reported C repro on 2023/07/01 21:31
android-6-12 general protection fault in do_unlinkat 2 C 2 31m 1h20m 0/1 premoderation: reported C repro on 2025/07/15 16:32
android-5-15 general protection fault in do_unlinkat origin:downstream 2 C done 10 10d 744d 0/2 upstream: reported C repro on 2023/07/01 22:19
Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/07/12 09:05 11m retest repro android14-6.1 report log
2025/06/28 08:46 6m retest repro android14-6.1 report log
2025/06/08 08:13 14m retest repro android14-6.1 report log
2025/06/08 08:13 10m retest repro android14-6.1 report log
2025/05/15 15:27 1h14m retest repro android14-6.1 report log
2025/03/30 01:17 1h04m retest repro android14-6.1 report log
2025/03/30 01:17 13m retest repro android14-6.1 report log
2025/03/05 07:21 10m retest repro android14-6.1 report log
2025/01/18 14:10 13m retest repro android14-6.1 report log
2025/01/18 14:10 14m retest repro android14-6.1 report log
Fix bisection attempts (13)
Created Duration User Patch Repo Result
2025/04/30 22:27 1h25m bisect fix android14-6.1 OK (0) job log log
2025/02/19 06:30 46m bisect fix android14-6.1 OK (0) job log log
2024/12/17 15:41 2h30m bisect fix android14-6.1 OK (0) job log log
2024/10/21 06:17 1h50m bisect fix android14-6.1 OK (0) job log log
2024/09/20 02:34 1h45m bisect fix android14-6.1 OK (0) job log log
2024/07/23 18:56 1h43m bisect fix android14-6.1 OK (0) job log log
2024/05/25 10:12 44m bisect fix android14-6.1 OK (0) job log log
2024/03/21 00:11 1h00m bisect fix android14-6.1 OK (0) job log log
2024/02/19 22:19 1h23m bisect fix android14-6.1 OK (0) job log log
2024/01/09 15:22 39m bisect fix android14-6.1 OK (0) job log log
2023/12/10 14:41 40m bisect fix android14-6.1 OK (0) job log log
2023/11/10 12:19 45m bisect fix android14-6.1 OK (0) job log log
2023/09/09 05:16 38m bisect fix android14-6.1 OK (0) job log log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 1 PID: 292 Comm: syz-executor691 Not tainted 6.1.138-syzkaller-00002-g13ff1300ee84 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:do_unlinkat+0x27d/0x6b0 fs/namei.c:4381
Code: 44 89 ee e8 45 b2 af ff 45 31 e4 41 81 fd 00 00 20 00 41 0f 95 c4 41 83 c4 eb e9 bd 00 00 00 49 8d 7e 30 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 4c 8b 7c 24 18 74 05 e8 02 05 f4 ff 49 8b 46 30 48
RSP: 0018:ffffc90000e67e00 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 1ffff110229dba06 RCX: 0000000000000000
RDX: ffff88810e5e5100 RSI: 0000000000000000 RDI: 0000000000000038
RBP: ffffc90000e67ee8 R08: dffffc0000000000 R09: fffff520001ccf9d
R10: fffff520001ccf9d R11: 1ffff920001ccf9c R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000008 R15: 0000000000000000
FS:  00007fa5fae506c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056191fb9beb8 CR3: 0000000126859000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __do_sys_unlink fs/namei.c:4437 [inline]
 __se_sys_unlink fs/namei.c:4435 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4435
 x64_sys_call+0x958/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:88
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa5faeaf479
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa5fae50218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fa5faf3c3f8 RCX: 00007fa5faeaf479
RDX: 00007fa5faeaf479 RSI: 00000000000f4240 RDI: 0000200000000100
RBP: 00007fa5faf3c3f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa5faf09034
R13: 0000200000004300 R14: 0000200000000100 R15: 00007ffcc576e718
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_unlinkat+0x27d/0x6b0 fs/namei.c:4381
Code: 44 89 ee e8 45 b2 af ff 45 31 e4 41 81 fd 00 00 20 00 41 0f 95 c4 41 83 c4 eb e9 bd 00 00 00 49 8d 7e 30 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 4c 8b 7c 24 18 74 05 e8 02 05 f4 ff 49 8b 46 30 48
RSP: 0018:ffffc90000e67e00 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 1ffff110229dba06 RCX: 0000000000000000
RDX: ffff88810e5e5100 RSI: 0000000000000000 RDI: 0000000000000038
RBP: ffffc90000e67ee8 R08: dffffc0000000000 R09: fffff520001ccf9d
R10: fffff520001ccf9d R11: 1ffff920001ccf9c R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000008 R15: 0000000000000000
FS:  00007fa5fae506c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056191fb9beb8 CR3: 0000000126859000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	44 89 ee             	mov    %r13d,%esi
   3:	e8 45 b2 af ff       	call   0xffafb24d
   8:	45 31 e4             	xor    %r12d,%r12d
   b:	41 81 fd 00 00 20 00 	cmp    $0x200000,%r13d
  12:	41 0f 95 c4          	setne  %r12b
  16:	41 83 c4 eb          	add    $0xffffffeb,%r12d
  1a:	e9 bd 00 00 00       	jmp    0xdc
  1f:	49 8d 7e 30          	lea    0x30(%r14),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	4c 8b 7c 24 18       	mov    0x18(%rsp),%r15
  34:	74 05                	je     0x3b
  36:	e8 02 05 f4 ff       	call   0xfff4053d
  3b:	49 8b 46 30          	mov    0x30(%r14),%rax
  3f:	48                   	rex.W

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/10 23:33 android14-6.1 13ff1300ee84 5d7e17ca .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
2025/01/04 13:57 android14-6.1 e2b9748880b9 f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
2024/12/30 15:14 android14-6.1 3f924195e222 d3ccff63 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
2024/03/30 12:22 android14-6.1 5b8114ec3c92 6baf5069 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
2023/07/01 22:18 android14-6.1 ed2a228522b9 bfc47836 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
2024/04/20 13:57 android14-6.1 dcb09569bbff af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
2023/10/08 18:43 android14-6.1 1fe248991f96 5e837c76 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_unlinkat
* Struck through repros no longer work on HEAD.