Re: KASAN: use-after-free Read in locks_delete_block

From: Jeff Layton
Date: Tue Nov 20 2018 - 06:08:40 EST


On Tue, 2018-11-20 at 07:57 +0100, Dmitry Vyukov wrote:
> On Sat, Nov 17, 2018 at 3:03 PM, Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
> > On Sat, Nov 17, 2018 at 08:33:27AM -0500, Jeff Layton wrote:
> > > Thanks for the explanation, Dmitry. I've added the tag to the patch in
> > > my tree. It should show up in linux-next soon.
> > >
> > > I still find it a little misleading to say that syzbot reported a bug
> > > when it actually found a bug inside an earlier version of the patch, but
> > > I'll just learn to get over it.
> >
> > The usual tag for someone that found a bug in an earlier version of a
> > patch would be Reviewed-by:. Is there any reason we can't use that
> > here? The "syzbot+..." email should be enough on its own, I can't see a
> > reason why their scripts would need to require a particular tag. Or
> > maybe we could use Tested-by:, or some other tag made up for this case?
> >
> > I do worry that someone who sees "Reported-by:..." might for example
> > mistakenly assume that it would help to backport that patch if they see
> > a similar-looking oops.
>
> I see. It may also be picked by scripts that detects patches that need
> to be backported to stable because of the "Reported-by: syzbot" tag.
> This is somewhat unfortunate.
>
> There is no problem parsing another tag on syzbot side. Does Tested-by
> look good to you? If it found a bug in the patch and then it was
> fixed, Tested-by looks reasonable. And we also detect
> Reported-and-tested-by already because that's what syzbot suggests
> after it tested a proposed fix for a bug.
>
> I am somewhat concerned how to spread this information across all
> kernel developers. There is effectively no way to do this. We can't
> expect people to read docs, they generally don't. I guess I just
> document this at "See https://goo.gl/tpsmEJ for more information" and
> then we can point other people there if/when this concern pops up
> again.

Tested-by sounds like it might be a reasonable fit. I'll change the
patch in my tree to read that way.

Thanks,
--
Jeff Layton <jlayton@xxxxxxxxxx>