syzbot


general protection fault in do_rmdir

Status: upstream: reported C repro on 2023/12/08 13:26
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+8f2a09a274a49e1a0dc3@syzkaller.appspotmail.com
First crash: 193d, last: 9d06h
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: BUG: unable to handle kernel NULL pointer dereference in do_rmdir (log)
Repro: C syz .config
  
Bug presence (3)
Date Name Commit Repro Result
2023/12/04 android14-6.1 (ToT) 6465e29536ed C [report] general protection fault in do_rmdir
2023/12/04 lts (merge base) 082280fe94a0 C Didn't crash
2023/12/04 upstream (ToT) 33cc938e65a9 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_rmdir C 9 17d 189d 0/2 upstream: reported C repro on 2023/12/08 13:26
android-5-15 general protection fault in do_rmdir origin:downstream C 3 22d 189d 0/2 upstream: reported C repro on 2023/12/08 13:26
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/06/05 21:39 6m retest repro android14-6.1 report log
2024/04/18 00:17 8m retest repro android14-6.1 report log
Fix bisection attempts (4)
Created Duration User Patch Repo Result
2024/05/22 20:59 38m bisect fix android14-6.1 job log (0) log
2024/03/14 08:23 1h38m bisect fix android14-6.1 job log (0) log
2024/02/10 20:42 48m bisect fix android14-6.1 job log (0) log
2024/01/03 19:03 1h26m bisect fix android14-6.1 job log (0) 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: 295 Comm: syz-executor105 Not tainted 6.1.75-syzkaller-00112-gaf361f9a1066 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:do_rmdir+0x33f/0x630 fs/namei.c:4251
Code: ff 4c 89 64 24 50 72 0d e8 1e cf ac ff 45 89 fc e9 99 00 00 00 49 8d 5f 30 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 43 aa f3 ff 48 83 3b 00 74 5d e8 e8
RSP: 0018:ffffc90000e27de0 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffffc90000e27f08 R08: ffffffff81cb158b R09: fffff520001c4f9d
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88811f5348b0
R13: ffffc90000e27e60 R14: 1ffff11023ea6916 R15: 0000000000000008
FS:  00007f98168126c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9816812d58 CR3: 0000000121771000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __do_sys_rmdir fs/namei.c:4278 [inline]
 __se_sys_rmdir fs/namei.c:4276 [inline]
 __x64_sys_rmdir+0x49/0x50 fs/namei.c:4276
 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: 0033:0x7f98168713f9
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:00007f9816812218 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f98168fd3f8 RCX: 00007f98168713f9
RDX: 00007f98168713f9 RSI: 0000000000000000 RDI: 0000000020000200
RBP: 00007f98168fd3f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffe2b485437 R11: 0000000000000246 R12: 00007f98168ca01c
R13: 00007f98168ca038 R14: 00007ffe2b485350 R15: 0030656c69662f30
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_rmdir+0x33f/0x630 fs/namei.c:4251
Code: ff 4c 89 64 24 50 72 0d e8 1e cf ac ff 45 89 fc e9 99 00 00 00 49 8d 5f 30 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 43 aa f3 ff 48 83 3b 00 74 5d e8 e8
RSP: 0018:ffffc90000e27de0 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffffc90000e27f08 R08: ffffffff81cb158b R09: fffff520001c4f9d
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88811f5348b0
R13: ffffc90000e27e60 R14: 1ffff11023ea6916 R15: 0000000000000008
FS:  00007f98168126c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9816812d58 CR3: 0000000121771000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	ff 4c 89 64          	decl   0x64(%rcx,%rcx,4)
   4:	24 50                	and    $0x50,%al
   6:	72 0d                	jb     0x15
   8:	e8 1e cf ac ff       	call   0xffaccf2b
   d:	45 89 fc             	mov    %r15d,%r12d
  10:	e9 99 00 00 00       	jmp    0xae
  15:	49 8d 5f 30          	lea    0x30(%r15),%rbx
  19:	48 89 d8             	mov    %rbx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	48 89 df             	mov    %rbx,%rdi
  33:	e8 43 aa f3 ff       	call   0xfff3aa7b
  38:	48 83 3b 00          	cmpq   $0x0,(%rbx)
  3c:	74 5d                	je     0x9b
  3e:	e8                   	.byte 0xe8
  3f:	e8                   	.byte 0xe8

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/04 00:13 android14-6.1 af361f9a1066 51c4dcff .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_rmdir
2023/12/04 16:26 android14-6.1 6465e29536ed f819d6f7 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in do_rmdir
* Struck through repros no longer work on HEAD.