Reduce the attack vector and stop generating IPv6 Fragment Header for paths with an MTU smaller than the minimum required IPv6 MTU size (1280 byte) - called atomic fragments.
See IETF I-D "Deprecating the Generation of IPv6 Atomic Fragments" [1] for more information and how this "feature" can be misused. [1] https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-00 Cc: stable@vger.kernel.org Signed-off-by: Fernando Gont <fg...@si6networks.com> Signed-off-by: Hagen Paul Pfeifer <ha...@jauu.net> --- net/ipv6/route.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 34dcbb5..d4603fb 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1160,12 +1160,9 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct net *net = dev_net(dst->dev); rt6->rt6i_flags |= RTF_MODIFIED; - if (mtu < IPV6_MIN_MTU) { - u32 features = dst_metric(dst, RTAX_FEATURES); + if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; - features |= RTAX_FEATURE_ALLFRAG; - dst_metric_set(dst, RTAX_FEATURES, features); - } + dst_metric_set(dst, RTAX_MTU, mtu); rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires); } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
