Re: [syzbot] KASAN: use-after-free Read in __media_entity_remove_links

[Aleksandr Nogikh]

Thanks for reporting the problem!

Syzbot looked at the last ~1.5 years of commit history to find the
commit, which is almost always enough, but not in this particular
case.

I've filed https://github.com/google/syzkaller/issues/4347 to fix the
syzbot code.

-- 
Aleksandr

On Tue, Nov 21, 2023 at 10:45 PM Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Nov 21, 2023 at 01:13:15PM -0800, syzbot wrote:
> > This bug is marked as fixed by commit:
> > media: uvcvideo: Avoid cyclic entity chains due to malformed USB descriptors
> >
> > But I can't find it in the tested trees[1] for more than 90 days.
> > Is it a correct commit? Please update it by replying:
> >
> > #syz fix: exact-commit-title
>
> What logic does syzbot use to try and find the commit upstream ? There's
> a commit with the exact same subject, what was missing to find it
> automatically ?
>
> > Until then the bug is still considered open and new crashes with
> > the same signature are ignored.
> >
> > Kernel: Linux
> > Dashboard link: https://syzkaller.appspot.com/bug?extid=0b0095300dfeb8a83dc8
> >
> > ---
> > [1] I expect the commit to be present in:
> >
> > 1. for-kernelci branch of
> > git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
> >
> > 2. master branch of
> > git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git
> >
> > 3. master branch of
> > git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git
> >
> > 4. main branch of
> > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
> >
> > The full list of 9 trees can be found at
> > https://syzkaller.appspot.com/upstream/repos
>
> --
> Regards,
>
> Laurent Pinchart