Re: [syzbot] [overlayfs?] WARNING in ovl_workdir_create (3)

From: Aleksandr Nogikh
Date: Fri May 17 2024 - 11:43:44 EST


On Fri, May 17, 2024 at 5:41 PM 'Miklos Szeredi' via syzkaller-bugs
<syzkaller-bugs@xxxxxxxxxxxxxxxx> wrote:
>
> On Mon, 13 May 2024 at 20:28, syzbot
> <syzbot+8aa3f99a6acb9f8fd429@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 45db3ab70092 Merge tag '6.9-rc7-ksmbd-fixes' of git://git...
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=169b934c980000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=2f7a2b43b9e58995
> > dashboard link: https://syzkaller.appspot.com/bug?extid=8aa3f99a6acb9f8fd429
> > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> >
> > Unfortunately, I don't have any reproducer for this issue yet.
> >
> > Downloadable assets:
> > disk image: https://storage.googleapis.com/syzbot-assets/0c2a8034002c/disk-45db3ab7.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/807e35e2b3a9/vmlinux-45db3ab7.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/4868b2eab91a/bzImage-45db3ab7.xz
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+8aa3f99a6acb9f8fd429@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > ------------[ cut here ]------------
> > DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888077f311f0, owner = 0x0, curr 0xffff8880787ebc00, list empty
>
> This is lock corruption on the upper filesystem, definitely not an
> overlayfs issue.
>
> #syz unset subsystems
>
> Thanks,
> Miklos
>
> --

Let's set ext4 then:

#syz set subsystems: ext4