From: Li Wei <lw@xxxxxxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 3cdaa5be9e81a914e633a6be7b7d2ef75b528562 upstream. RFC 1191 said, "a host MUST not increase its estimate of the Path MTU in response to the contents of a Datagram Too Big message." Signed-off-by: Li Wei <lw@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- net/ipv4/route.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index bd5f3461d1ce..fe0c761a8fce 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -988,6 +988,9 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) if (dst->dev->mtu < mtu) return; + if (rt->rt_pmtu && rt->rt_pmtu < mtu) + return; + if (mtu < ip_rt_min_pmtu) mtu = ip_rt_min_pmtu; -- 2.7.0 -- 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