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(). -- 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
