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: 349d, last: 6d17h
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 (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in do_unlinkat C done 11 2d13h 349d 0/2 upstream: reported C repro on 2023/07/01 21:31
android-5-15 general protection fault in do_unlinkat origin:downstream C done 2 12d 349d 0/2 upstream: reported C repro on 2023/07/01 22:19
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/06/08 11:17 5m retest repro android14-6.1 report log
2024/04/13 14:49 32m retest repro android14-6.1 report log
Fix bisection attempts (7)
Created Duration User Patch Repo Result
2024/05/25 10:12 44m bisect fix android14-6.1 job log (0) log
2024/03/21 00:11 1h00m bisect fix android14-6.1 job log (0) log
2024/02/19 22:19 1h23m bisect fix android14-6.1 job log (0) log
2024/01/09 15:22 39m bisect fix android14-6.1 job log (0) log
2023/12/10 14:41 40m bisect fix android14-6.1 job log (0) log
2023/11/10 12:19 45m bisect fix android14-6.1 job log (0) log
2023/09/09 05:16 38m bisect fix android14-6.1 job log (0) log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
CPU: 0 PID: 296 Comm: syz-executor383 Not tainted 6.1.68-syzkaller-00100-g5b8114ec3c92 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:do_unlinkat+0x3db/0x910 fs/namei.c:4312
Code: de e8 49 ce ac 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 09 9e f3 ff 49 8b 45 30 48 89 44 24 38 4c
RSP: 0018:ffffc90000e47d80 EFLAGS: 00010206
RAX: 0000000000000009 RBX: 0000000000000000 RCX: ffff88811ce0a880
RDX: ffff88811ce0a880 RSI: 0000000000000000 RDI: 0000000000000049
RBP: ffffc90000e47f08 R08: ffffffff81c8a68c R09: fffff520001c8f8f
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000019 R14: dffffc0000000000 R15: 1ffff11023e2286c
FS:  00007f92d603e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002080 CR3: 000000010945e000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __do_sys_unlink fs/namei.c:4368 [inline]
 __se_sys_unlink fs/namei.c:4366 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4366
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f92d609d589
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:00007f92d603e218 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f92d612a3f8 RCX: 00007f92d609d589
RDX: 00007f92d609d589 RSI: 00000000000f4240 RDI: 0000000020000100
RBP: 00007f92d612a3f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f92d60f7024
R13: 000000000000006e R14: 0030656c69662f30 R15: 2f30656c69662f2e
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_unlinkat+0x3db/0x910 fs/namei.c:4312
Code: de e8 49 ce ac 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 09 9e f3 ff 49 8b 45 30 48 89 44 24 38 4c
RSP: 0018:ffffc90000e47d80 EFLAGS: 00010206
RAX: 0000000000000009 RBX: 0000000000000000 RCX: ffff88811ce0a880
RDX: ffff88811ce0a880 RSI: 0000000000000000 RDI: 0000000000000049
RBP: ffffc90000e47f08 R08: ffffffff81c8a68c R09: fffff520001c8f8f
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000019 R14: dffffc0000000000 R15: 1ffff11023e2286c
FS:  00007f92d603e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f92d603ed58 CR3: 000000010945e000 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:	49 ce                	rex.WB (bad)
   4:	ac                   	lods   %ds:(%rsi),%al
   5:	ff 31                	push   (%rcx)
   7:	c0 81 fb 00 00 20 00 	rolb   $0x0,0x200000fb(%rcx)
   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 09 9e f3 ff       	call   0xfff39e3f
  36:	49 8b 45 30          	mov    0x30(%r13),%rax
  3a:	48 89 44 24 38       	mov    %rax,0x38(%rsp)
  3f:	4c                   	rex.WR

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.