On Wed, Feb 14, 2018 at 01:30:37PM +0100, Florian Westphal wrote:
> Eric Dumazet <eric.duma...@gmail.com> wrote:
> > On Wed, 2018-02-14 at 12:13 +0100, Paolo Abeni wrote:
> > > syzbot reported a division by 0 bug in the netfilter nat code:
> >
> > > Adding the relevant check at parse time could break existing
> > > setup, moreover we would need to read/write such values atomically
> > > to avoid possible transient negative ranges at update time.
> >
> > I do not quite follow why it is so hard to add a check at parse time.
> >
> > Breaking buggy setups would not be a concern I think.
>
> It would be possible for xtables but afaics in nft_nat.c case
> (nft_nat_eval) range.{min,max}_proto.all values are loaded from nft
> registers at runtime.
Then, restrict this from nft_nat.
