syzbot


general protection fault in do_rmdir

Status: upstream: reported C repro on 2023/12/08 13:26
Reported-by: syzbot+86ab3204ce3bfdb7de7a@syzkaller.appspotmail.com
First crash: 94d, last: 16d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 general protection fault in do_rmdir origin:downstream C 2 20d 87d 0/2 upstream: reported C repro on 2023/12/08 13:26
android-6-1 general protection fault in do_rmdir origin:downstream C done 1 23d 87d 0/2 upstream: reported C repro on 2023/12/08 13:26
Last patch testing requests (1)
Created Duration User Patch Repo Result
2023/12/16 04:35 9m retest repro android13-5.10-lts report log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/02/17 22:45 1h13m bisect fix android13-5.10-lts job log (0) log
2024/01/16 05:56 39m bisect fix android13-5.10-lts 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: 287 Comm: syz-executor210 Not tainted 5.10.200-syzkaller-00425-g0da9a7bcb7a2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:do_rmdir+0x28e/0x5c0 fs/namei.c:3911
Code: e8 87 c3 b6 ff 45 89 e5 48 bb 00 00 00 00 00 fc ff df eb 7c 49 8d 5c 24 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 14 34 f4 ff 48 83 3b 00 74 32 e8 49
RSP: 0018:ffffc90000b97de0 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffffc90000b97f18 R08: ffffffff81b64f7b R09: ffffed1023810250
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000008
R13: ffff88811c081250 R14: 1ffff1102381024a R15: ffffc90000b97e01
FS:  00007f6e6bd696c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000400 CR3: 000000011ea44000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __do_sys_rmdir fs/namei.c:3936 [inline]
 __se_sys_rmdir fs/namei.c:3934 [inline]
 __x64_sys_rmdir+0x49/0x50 fs/namei.c:3934
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7f6e6bda7479
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:00007f6e6bd69218 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f6e6be34408 RCX: 00007f6e6bda7479
RDX: 00007f6e6bda7479 RSI: 00000000000f4240 RDI: 0000000020000080
RBP: 00007f6e6be34400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6e6be0101c
R13: 00007f6e6be01038 R14: 00007f6e6bdff00e R15: 0030656c69662f30
Modules linked in:
---[ end trace c9bc1d7d8939e43b ]---
RIP: 0010:do_rmdir+0x28e/0x5c0 fs/namei.c:3911
Code: e8 87 c3 b6 ff 45 89 e5 48 bb 00 00 00 00 00 fc ff df eb 7c 49 8d 5c 24 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 14 34 f4 ff 48 83 3b 00 74 32 e8 49
RSP: 0018:ffffc90000b97de0 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000038 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: ffffc90000b97f18 R08: ffffffff81b64f7b R09: ffffed1023810250
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000008
R13: ffff88811c081250 R14: 1ffff1102381024a R15: ffffc90000b97e01
FS:  00007f6e6bd696c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e6bd27d58 CR3: 000000011ea44000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 87 c3 b6 ff       	call   0xffb6c38c
   5:	45 89 e5             	mov    %r12d,%r13d
   8:	48 bb 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbx
   f:	fc ff df
  12:	eb 7c                	jmp    0x90
  14:	49 8d 5c 24 30       	lea    0x30(%r12),%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 14 34 f4 ff       	call   0xfff4344c
  38:	48 83 3b 00          	cmpq   $0x0,(%rbx)
  3c:	74 32                	je     0x70
  3e:	e8                   	.byte 0xe8
  3f:	49                   	rex.WB

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/02 04:21 android13-5.10-lts 0da9a7bcb7a2 f819d6f7 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in do_rmdir
2023/12/02 03:52 android13-5.10-lts 0da9a7bcb7a2 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in do_rmdir
* Struck through repros no longer work on HEAD.