syzbot


general protection fault in ext4_acquire_dquot

Status: auto-obsoleted due to no activity on 2024/01/03 10:28
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+c0cc0a5cb98ffbf49add@syzkaller.appspotmail.com
First crash: 547d, last: 423d
Cause bisection: introduced by (bisect log) :
commit a9f2a2931d0e197ab28c6007966053fdababd53f
Author: Jan Kara <jack@suse.cz>
Date: Thu Sep 8 09:21:27 2022 +0000

  ext4: use locality group preallocation for small closed files

Crash: general protection fault in ext4_acquire_dquot (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit dba62fa84a8eac44a53a2862de8a40e5bdfa0ae3
Author: Ye Bin <yebin10@huawei.com>
Date: Mon Jan 16 02:00:15 2023 +0000

  ext4: fix WARNING in mb_find_extent

  
Bug presence (2)
Date Name Commit Repro Result
2023/05/24 lts (merge base) b1644a0031cf C [report] general protection fault in ext4_acquire_dquot
2023/05/24 upstream (ToT) 9d646009f65d C Didn't crash
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 BUG: unable to handle kernel paging request in ext4_acquire_dquot origin:lts-only C done 2 521d 556d 3/3 fixed on 2023/08/04 15:57
upstream general protection fault in ext4_acquire_dquot ext4 C 4 519d 559d 23/28 fixed on 2023/10/12 12:47
android-5-15 general protection fault in ext4_acquire_dquot C done done 2 515d 547d 2/2 fixed on 2023/09/06 18:13
Fix bisection attempts (4)
Created Duration User Patch Repo Result
2023/10/27 21:11 3h03m bisect fix android14-6.1 OK (1) job log
2023/09/25 09:41 46m bisect fix android14-6.1 OK (0) job log log
2023/08/12 13:19 1h15m bisect fix android14-6.1 OK (0) job log log
2023/06/25 14:51 45m bisect fix android14-6.1 OK (0) job log log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 0 PID: 394 Comm: syz-executor375 Tainted: G        W          6.1.25-syzkaller-00265-g86a6bbdc8ffe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
RIP: 0010:ext4_acquire_dquot+0x22b/0x3f0 fs/ext4/super.c:6740
Code: 9c d8 60 01 00 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 93 49 b9 ff 4c 8b 33 49 83 c6 28 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 76 49 b9 ff bb a8 03 00 00 49 03
RSP: 0018:ffffc90000f874b8 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff888109aee160 RCX: ffff88811c0d5f00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffffc90000f87508 R08: ffffffff81ffcafc R09: ffffed1024319039
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000162
R13: 0000000000000049 R14: 0000000000000028 R15: dffffc0000000000
FS:  00007fdac2c64700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdaba883000 CR3: 000000010fe73000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dqget+0x9bc/0xdc0 fs/quota/dquot.c:914
 __dquot_initialize+0x2d9/0xe10 fs/quota/dquot.c:1492
 dquot_initialize fs/quota/dquot.c:1550 [inline]
 dquot_file_open+0x83/0xb0 fs/quota/dquot.c:2181
 ext4_file_open+0x308/0x750 fs/ext4/file.c:893
 do_dentry_open+0x891/0x1250 fs/open.c:884
 vfs_open+0x73/0x80 fs/open.c:1015
 do_open fs/namei.c:3557 [inline]
 path_openat+0x2532/0x2d60 fs/namei.c:3714
 do_filp_open+0x230/0x480 fs/namei.c:3741
 do_sys_openat2+0x13f/0x850 fs/open.c:1333
 do_sys_open fs/open.c:1349 [inline]
 __do_sys_openat fs/open.c:1365 [inline]
 __se_sys_openat fs/open.c:1360 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1360
 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+0x63/0xcd
RIP: 0033:0x7fdac2cb88e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 15 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdac2c64208 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fdac2d3d7a8 RCX: 00007fdac2cb88e9
RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007fdac2d3d7a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdac2d3d7ac
R13: 00007fffc02c93ff R14: 00007fdac2c64300 R15: 0000000000022000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_acquire_dquot+0x22b/0x3f0 fs/ext4/super.c:6740
Code: 9c d8 60 01 00 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 93 49 b9 ff 4c 8b 33 49 83 c6 28 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 76 49 b9 ff bb a8 03 00 00 49 03
RSP: 0018:ffffc90000f874b8 EFLAGS: 00010206
RAX: 0000000000000005 RBX: ffff888109aee160 RCX: ffff88811c0d5f00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffffc90000f87508 R08: ffffffff81ffcafc R09: ffffed1024319039
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000162
R13: 0000000000000049 R14: 0000000000000028 R15: dffffc0000000000
FS:  00007fdac2c64700(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc02c839c CR3: 000000010fe73000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	9c                   	pushfq
   1:	d8 60 01             	fsubs  0x1(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	48 89 d8             	mov    %rbx,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
  12:	74 08                	je     0x1c
  14:	48 89 df             	mov    %rbx,%rdi
  17:	e8 93 49 b9 ff       	callq  0xffb949af
  1c:	4c 8b 33             	mov    (%rbx),%r14
  1f:	49 83 c6 28          	add    $0x28,%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 76 49 b9 ff       	callq  0xffb949af
  39:	bb a8 03 00 00       	mov    $0x3a8,%ebx
  3e:	49                   	rex.WB
  3f:	03                   	.byte 0x3

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/24 09:31 android14-6.1 86a6bbdc8ffe 4bce1a3e .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-6-1 general protection fault in ext4_acquire_dquot
* Struck through repros no longer work on HEAD.