net:dccp: do not report ICMP redirects to user space

[ Upstream commit bd784a14 ]

DCCP shouldn't be setting sk_err on redirects as it
isn't an error condition. it should be doing exactly
what tcp is doing and leaving the error handler without
touching the socket.
Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/dccp/ipv6.c

@@ -135,6 +135,7 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 		if (dst)
 			dst->ops->redirect(dst, sk, skb);
+		goto out;
 	}
 
 	if (type == ICMPV6_PKT_TOOBIG) {