From: Hagen Paul Pfeifer <hagen@xxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 9d289715eb5c252ae15bd547cb252ca547a3c4f2 ] 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 Signed-off-by: Fernando Gont <fgont@xxxxxxxxxxxxxxx> Signed-off-by: Hagen Paul Pfeifer <hagen@xxxxxxxx> Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- 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 b4bb6a29aa16..1d0c5d66d637 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1144,12 +1144,9 @@ 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); } -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html