Missing skb->dst with flow offloading

[Pablo Neira Ayuso]

On Wed, May 30, 2018 at 08:14:42PM +0200, Jason A. Donenfeld wrote:
> Hey Pablo,
> 
> On Wed, May 30, 2018 at 8:05 PM, Pablo Neira Ayuso <pablo at netfilter.org> wrote:
> > If there a more drivers in-tree that need this, we may add
> > skb_dst_set_noref() calls to _hook function in the flowtable codebase.
> 
> Can I, then, take that as an implicit acknowledgement that this
> observed behavior on OpenWRT is to be expected with the current state
> of events, and that I should patch my driver accordingly?
> 
> As one example of this in tree, take a look at vxlan -- it's using it
> for the mtu/pmtu exactly as WireGuard does.

May it crash the kernel because it's assuming is set? If so, then
I'd appreciate if you send us a patch to
netfilter-devel at vger.kernel.org.

Please, use the nf-next.git tree to patch nf_flow_offload_ip_hook()
and nf_flow_offload_ip6_hook(), it's rather late, we'll request a
-stable submission for this if needed.

Thanks.