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.