Re: [syzbot] [kernel?] WARNING in class_register

[Dmitry Vyukov]

On Sun, 2 Apr 2023 at 10:45, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sat, Apr 01, 2023 at 01:39:42PM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    a6d9e3034536 Add linux-next specific files for 20230330
> > git tree:       linux-next
> > console+strace: https://syzkaller.appspot.com/x/log.txt?x=1496edcdc80000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=aceb117f7924508e
> > dashboard link: https://syzkaller.appspot.com/bug?extid=ca3d9f693dfa69f61371
> > compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14f57859c80000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=167cc501c80000
> >
> > Downloadable assets:
> > disk image: https://storage.googleapis.com/syzbot-assets/ec1f900ea929/disk-a6d9e303.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/fabbf89c0d22/vmlinux-a6d9e303.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/1ed05d6192fa/bzImage-a6d9e303.xz
> >
> > The issue was bisected to:
> >
> > commit dcfbb67e48a2becfce7990386e985b9c45098ee5
> > Author: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Date:   Fri Mar 24 10:01:31 2023 +0000
> >
> >     driver core: class: use lock_class_key already present in struct subsys_private
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10190b49c80000
> > final oops:     https://syzkaller.appspot.com/x/report.txt?x=12190b49c80000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14190b49c80000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+ca3d9f693dfa69f61371@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Fixes: dcfbb67e48a2 ("driver core: class: use lock_class_key already present in struct subsys_private")
>
> Should already be fixed by:
>         https://lore.kernel.org/all/2023040126-blandness-duckling-bd55@gregkh/
> which was a different syzbot-reported issue with this same commit.

Let's tell syzbot so that it reports similar bugs in future:

#syz fix:
driver core: class : fix slab-use-after-free Read in class_register()