On 28 November 2016 at 16:45, Florian Westphal <[email protected]> wrote: > Eric Dumazet <[email protected]> wrote: >> On Mon, 2016-11-28 at 15:43 -0800, Daniele Di Proietto wrote: >> > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it >> > means that we still have a reference to the skb. We should free it >> > before returning from handle_fragments, as stated in the comment above. >> > >> > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") >> > CC: Florian Westphal <[email protected]> >> > CC: Pravin B Shelar <[email protected]> >> > CC: Joe Stringer <[email protected]> >> > Signed-off-by: Daniele Di Proietto <[email protected]> >> > --- >> > net/openvswitch/conntrack.c | 5 ++++- >> > 1 file changed, 4 insertions(+), 1 deletion(-) >> > >> > diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c >> > index 31045ef..fecefa2 100644 >> > --- a/net/openvswitch/conntrack.c >> > +++ b/net/openvswitch/conntrack.c >> > @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct >> > sw_flow_key *key, >> > skb_orphan(skb); >> > memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); >> > err = nf_ct_frag6_gather(net, skb, user); >> > - if (err) >> > + if (err) { >> > + if (err != -EINPROGRESS) >> > + kfree_skb(skb); >> > return err; >> > + } >> > >> > key->ip.proto = ipv6_hdr(skb)->nexthdr; >> > ovs_cb.mru = IP6CB(skb)->frag_max_size; >> >> Interesting, have you followed the "GPF in eth_header" thread today ? >> >> In a nutshell, we want a complete patch, not something that would solve >> part of the problem. > > I think this patch is fine, intent seems to be to only take fully reassembled > skb, rather than a stray fragment (ovs does NOT seem to call handle_fragments > in case skb is already known to not contain a fragment header, afaics).
Correct, this is used in OVS only for fragmented packets and this function either morphs the skb into the full skb fragment chain, or steals/frees the skb. > I'll send a patch for the GPF in eth_header thing soon.
