xfrm4: Don't call icmp_send on local error

Calling icmp_send() on a local message size error leads to
an incorrect update of the path mtu. So use ip_local_error()
instead to notify the socket about the error.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index 2d51840e53a1..327a617d594c 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -32,7 +32,12 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb)
         dst = skb_dst(skb);
         mtu = dst_mtu(dst);
         if (skb->len > mtu) {
-                icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+                if (skb->sk)
+                        ip_local_error(skb->sk, EMSGSIZE, ip_hdr(skb)->daddr,
+                                       inet_sk(skb->sk)->inet_dport, mtu);
+                else
+                        icmp_send(skb, ICMP_DEST_UNREACH,
+                                  ICMP_FRAG_NEEDED, htonl(mtu));
                 ret = -EMSGSIZE;
         }
 out: