On Fri, Apr 14, 2017 at 02:26:38PM -0700, Jarno Rajahalme wrote: > Conntrack helpers do not check for a potentially clashing conntrack > entry when creating a new expectation. Also, nf_conntrack_in() will > check expectations (via init_conntrack()) only if a conntrack entry > can not be found. The expectation for a packet which also matches an > existing conntrack entry will not be removed by conntrack, and is > currently handled inconsistently by OVS, as OVS expects the > expectation to be removed when the connection tracking entry matching > that expectation is confirmed. > > It should be noted that normally an IP stack would not allow reuse of > a 5-tuple of an old (possibly lingering) connection for a new data > connection, so this is somewhat unlikely corner case. However, it is > possible that a misbehaving source could cause conntrack entries be > created that could then interfere with new related connections. > > Fix this in the OVS module by deleting the clashing conntrack entry > after an expectation has been matched. This causes the following > nf_conntrack_in() call also find the expectation and remove it when > creating the new conntrack entry, as well as the forthcoming reply > direction packets to match the new related connection instead of the > old clashing conntrack entry. Applied, with minor changes that we have already discussed here. Thanks. -- 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
