tcp: Use correct peer adr when copying MD5 keys

When the TCP connection handshake completes on the passive
side, a variety of state must be set up in the "child" sock,
including the key if MD5 authentication is being used.  Fix TCP
for both address families to label the key with the peer's
destination address, rather than the address from the listening
sock, which is usually the wildcard.

Reported-by:   Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: John Dykstra <john.dykstra1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_ipv4.c

@@ -1374,7 +1374,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 		 */
 		char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
 		if (newkey != NULL)
-			tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
+			tcp_v4_md5_do_add(newsk, newinet->daddr,
 					  newkey, key->keylen);
 		newsk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 	}

net/ipv6/tcp_ipv6.c

@@ -1442,7 +1442,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 		 */
 		char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
 		if (newkey != NULL)
-			tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
+			tcp_v6_md5_do_add(newsk, &newnp->daddr,
 					  newkey, key->keylen);
 	}
 #endif