Re: [PATCH v4 1/2] netfilter: Terminate rule eval if protocol=IPv6 and ipv6 module is disabled

From: Pablo Neira Ayuso
Date: Tue Sep 03 2019 - 16:55:17 EST


On Tue, Sep 03, 2019 at 10:35:31PM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote:
> > On Tue, Sep 03, 2019 at 09:48:09PM +0200, Florian Westphal wrote:
> > > We could do that from nft_do_chain_netdev().
> >
> > Indeed, this is all about the netdev case.
> >
> > Probably add something similar to nf_ip6_route() to deal with
> > ip6_route_lookup() case? This is the one trigering the problem, right?
>
> Yes, this particular problem is caused by ipv6 fib not being
> initialized due to ipv6.disable=1. I don't know if there are cases
> other than FIB.
>
> > BTW, how does nft_fib_ipv6 module kicks in if ipv6 module is not
> > loaded? The symbol dependency would pull in the IPv6 module anyway.
>
> ipv6.disabled=1 does load the ipv6 module, but its non-functional.

I see, thanks for explaining.