1 files changed, 11 insertions, 4 deletions

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 60415711563f..49aea94c9be3 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -527,9 +527,6 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
                 case ICMP_PORT_UNREACH:
                         /* Impossible event. */
                         return 0;
-                case ICMP_FRAG_NEEDED:
-                        /* Soft state for pmtu is maintained by IP core. */
-                        return 0;
                 default:
                         /* All others are translated to HOST_UNREACH.
                            rfc2003 contains "deep thoughts" about NET_UNREACH,
@@ -551,7 +548,17 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
                                 skb->dev,
                                 iph->daddr,
                                 iph->saddr);
-        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->dev->ifindex, 0, IPPROTO_IPV6, 0);
+                err = 0;
+                goto out;
+        }
+
+        if (t->parms.iph.daddr == 0)
                 goto out;
 
         err = 0;