1 files changed, 10 insertions, 4 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index f49047b79609..594cec35ac4d 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -516,9 +516,6 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                 case ICMP_PORT_UNREACH:
                         /* Impossible event. */
                         return;
-                case ICMP_FRAG_NEEDED:
-                        /* Soft state for pmtu is maintained by IP core. */
-                        return;
                 default:
                         /* All others are translated to HOST_UNREACH.
                            rfc2003 contains "deep thoughts" about NET_UNREACH,
@@ -538,7 +535,16 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                                 flags & GRE_KEY ?
                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
                                 p[1]);
-        if (t == NULL || t->parms.iph.daddr == 0 ||
+        if (t == NULL)
+                goto out;
+
+        if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
+                ipv4_update_pmtu(skb, dev_net(skb->dev), info,
+                                 t->parms.link, 0, IPPROTO_GRE, 0);
+                goto out;
+        }
+
+        if (t->parms.iph.daddr == 0 ||
             ipv4_is_multicast(t->parms.iph.daddr))
                 goto out;