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+401c1e2e29c32961e4bd@syzkaller.appspotmail.com
First crash: 500d, last: 15d
Cause bisection: introduced by (bisect log) :
commit f5f4199c102aa676998b42abff60d071385c1c0c
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 android13-5.15-lts (ToT) 241da2ad5601 C [report] general protection fault in do_unlinkat
2023/07/05 lts (merge base) f67653019430 C Didn't crash
2023/07/05 upstream (ToT) d528014517f2 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in do_unlinkat C done 32 2d14h 500d 0/2 upstream: reported C repro on 2023/07/01 21:31
android-6-1 general protection fault in do_unlinkat origin:downstream C done 4 8d02h 500d 0/2 upstream: reported C repro on 2023/07/01 22:19
Last patch testing requests (6)
Created Duration User Patch Repo Result
2024/10/28 07:56 11m retest repro android13-5.15-lts report log
2024/10/06 20:31 7m retest repro android13-5.15-lts report log
2024/08/16 12:51 1h06m retest repro android13-5.15-lts report log
2024/08/16 12:51 6m retest repro android13-5.15-lts report log
2024/06/02 11:41 11m retest repro android13-5.15-lts report log
2024/04/14 01:40 5m retest repro android13-5.15-lts report log
Fix bisection attempts (10)
Created Duration User Patch Repo Result
2024/09/17 13:13 1h22m bisect fix android13-5.15-lts OK (0) job log log
2024/07/11 16:28 1h26m bisect fix android13-5.15-lts OK (0) job log log
2024/05/18 03:36 33m bisect fix android13-5.15-lts OK (0) job log log
2024/03/24 11:03 33m bisect fix android13-5.15-lts OK (0) job log log
2024/02/23 09:37 55m bisect fix android13-5.15-lts OK (0) job log log
2024/01/14 09:47 59m bisect fix android13-5.15-lts OK (0) job log log
2023/12/12 22:13 1h08m bisect fix android13-5.15-lts OK (0) job log log
2023/11/12 14:11 35m bisect fix android13-5.15-lts OK (0) job log log
2023/10/12 05:03 33m bisect fix android13-5.15-lts OK (0) job log log
2023/09/11 07:30 33m bisect fix android13-5.15-lts 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: 0 PID: 298 Comm: syz-executor226 Not tainted 5.15.152-syzkaller-00143-g70e1a731d986 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:do_unlinkat+0x3e1/0x920 fs/namei.c:4340
Code: de e8 33 29 b2 ff 31 c0 81 fb 00 00 20 00 0f 94 c0 41 be ec ff ff ff 41 29 c6 e9 bd 00 00 00 49 8d 7d 30 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 83 5f f4 ff 49 8b 45 30 48 89 44 24 38 4c
RSP: 0018:ffffc900009d7d80 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000000 RCX: ffff8881242ebb40
RDX: ffff8881242ebb40 RSI: 0000000000000000 RDI: 000000000000003a
RBP: ffffc900009d7f08 R08: ffffffff81be1c92 R09: ffffed10232fb360
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 000000000000000a R14: dffffc0000000000 R15: 1ffff110232fb35a
FS:  00007f0201c766c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0201c76d58 CR3: 0000000122cfa000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __do_sys_unlink fs/namei.c:4396 [inline]
 __se_sys_unlink fs/namei.c:4394 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4394
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0201cd54b9
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:00007f0201c76218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f0201d623f8 RCX: 00007f0201cd54b9
RDX: 00007f0201cd54b9 RSI: 00000000000f4240 RDI: 0000000020000100
RBP: 00007f0201d623f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0201d2f034
R13: 000000000000006e R14: 0030656c69662f30 R15: 2f30656c69662f2e
 </TASK>
Modules linked in:
---[ end trace 90eb4e6b15bbcbb6 ]---
RIP: 0010:do_unlinkat+0x3e1/0x920 fs/namei.c:4340
Code: de e8 33 29 b2 ff 31 c0 81 fb 00 00 20 00 0f 94 c0 41 be ec ff ff ff 41 29 c6 e9 bd 00 00 00 49 8d 7d 30 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 83 5f f4 ff 49 8b 45 30 48 89 44 24 38 4c
RSP: 0018:ffffc900009d7d80 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000000 RCX: ffff8881242ebb40
RDX: ffff8881242ebb40 RSI: 0000000000000000 RDI: 000000000000003a
RBP: ffffc900009d7f08 R08: ffffffff81be1c92 R09: ffffed10232fb360
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 000000000000000a R14: dffffc0000000000 R15: 1ffff110232fb35a
FS:  00007f0201c766c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000202d258 CR3: 0000000122cfa000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	de e8                	fsubrp %st,%st(0)
   2:	33 29                	xor    (%rcx),%ebp
   4:	b2 ff                	mov    $0xff,%dl
   6:	31 c0                	xor    %eax,%eax
   8:	81 fb 00 00 20 00    	cmp    $0x200000,%ebx
   e:	0f 94 c0             	sete   %al
  11:	41 be ec ff ff ff    	mov    $0xffffffec,%r14d
  17:	41 29 c6             	sub    %eax,%r14d
  1a:	e9 bd 00 00 00       	jmp    0xdc
  1f:	49 8d 7d 30          	lea    0x30(%r13),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 83 5f f4 ff       	call   0xfff45fb9
  36:	49 8b 45 30          	mov    0x30(%r13),%rax
  3a:	48 89 44 24 38       	mov    %rax,0x38(%rsp)
  3f:	4c                   	rex.WR

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/02 09:49 android13-5.15-lts 70e1a731d986 1e9c4cf3 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in do_unlinkat
2024/03/31 00:41 android13-5.15-lts 993bed180178 6baf5069 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in do_unlinkat
2023/07/01 22:18 android13-5.15-lts 241da2ad5601 bfc47836 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in do_unlinkat
2024/10/13 23:31 android13-5.15-lts 5e4635681cf1 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in do_unlinkat
2024/08/02 09:06 android13-5.15-lts 70e1a731d986 1e9c4cf3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in do_unlinkat
* Struck through repros no longer work on HEAD.