syzbot


WARNING in ovl_create_real (2)

Status: upstream: reported on 2024/12/13 03:32
Subsystems: overlayfs
[Documentation on labels]
Reported-by: syzbot+db0356b67c48887188e2@syzkaller.appspotmail.com
First crash: 12d, last: 5d07h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [overlayfs?] WARNING in ovl_create_real (2) 0 (1) 2024/12/13 03:32
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in ovl_create_real overlayfs C unreliable 164 1140d 1208d 20/28 fixed on 2022/03/08 16:11

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 11155 at fs/overlayfs/dir.c:213 ovl_create_real+0x5ab/0x670 fs/overlayfs/dir.c:213
Modules linked in:
CPU: 0 UID: 0 PID: 11155 Comm: syz.2.1376 Not tainted 6.13.0-rc2-syzkaller-00382-gdccbe2047a5b #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ovl_create_real+0x5ab/0x670 fs/overlayfs/dir.c:213
Code: 89 e2 48 c7 c6 c0 c2 89 8b 48 c7 c7 90 4d 0d 90 e8 6a b3 ba 01 e9 d9 fb ff ff e8 b0 d4 ef fe e9 93 fc ff ff e8 a6 61 8d fe 90 <0f> 0b 90 4c 89 e3 49 c7 c4 fb ff ff ff e9 d5 fc ff ff e8 ce 15 0e
RSP: 0018:ffffc90003ddfc28 EFLAGS: 00010287
RAX: 0000000000001cf5 RBX: ffff888067972eb0 RCX: ffffc9000d0a1000
RDX: 0000000000080000 RSI: ffffffff830bed4a RDI: ffff888067972f18
RBP: 1ffff920007bbf86 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000004 R12: ffff888067972eb0
R13: 0000000000000000 R14: ffff88804ceead10 R15: 000000000000a000
FS:  0000000000000000(0000) GS:ffff88802b400000(0063) knlGS:00000000f5085b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000c2dee4f CR3: 000000006bf56000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ovl_create_upper fs/overlayfs/dir.c:334 [inline]
 ovl_create_or_link+0x2a4/0x800 fs/overlayfs/dir.c:632
 ovl_create_object+0x268/0x300 fs/overlayfs/dir.c:673
 vfs_symlink fs/namei.c:4669 [inline]
 vfs_symlink+0x3e8/0x660 fs/namei.c:4653
 do_symlinkat+0x263/0x310 fs/namei.c:4695
 __do_sys_symlink fs/namei.c:4716 [inline]
 __se_sys_symlink fs/namei.c:4714 [inline]
 __ia32_sys_symlink+0x74/0x90 fs/namei.c:4714
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f55579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f508555c EFLAGS: 00000296 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00000000200049c0 RCX: 00000000200059c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/16 06:48 upstream dccbe2047a5b 7cbfbb3a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ovl_create_real
2024/12/09 03:22 upstream 62b5a46999c7 9ac0fdc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in ovl_create_real
* Struck through repros no longer work on HEAD.