Patrick McHardy <kaber@xxxxxxxxx> wrote: > On 30.08.2011 14:54, Florian Westphal wrote: > > Patrick McHardy <kaber@xxxxxxxxx> wrote: > >> On 30.08.2011 12:57, Florian Westphal wrote: > >>> When incoking iptables hooks from bridge netfilter, the assumption > >>> that non-confirmed skb->nfct is never shared does no longer hold, > >>> as bridge code clones skbs when e.g. forwarding packets to multiple > >>> bridge ports. > >>> > >>> When NFQUEUE is used, we can BUG because nf_nat_setup_info can be > >>> invoked simultaneously for the same conntrack: > >> > >> I'm wondering how this can happen, when flooding packets to multiple > >> ports, they are still processed by the same CPU one after another, > >> so for the second and further packets, nf_nat should notice that > >> the mappings are already set up. > > > > Main problem is that we end up with same ->nfct in both > > INPUT and POSTROUTING (br_pass_frame_up vs. br_forward). > > > > its extremely unlikely but reproduceable with something like > > hping2 -i u1200 -2 -p 138 -d 128 192.168.0.255 > > > > (assuming bridge interface has an address within that network). > > > > Also, with recent change nf_reinject can be run in parallel. > > (the original problem was observed on 2.6.32.24, but i can > > reproduce it with nf-next, too). > > I see. We still need to avoid the module dependency on nf_conntrack > though, so I think this will have to be fixed in nf_nat_fn(). Right, I failed to spot the call to the destroy hook 8-/ I'll submit an alternate patch shortly. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
