ipv4: Fixed MD5 key lookups when adding/ removing MD5 to/ from TCP sockets.

MD5 key lookups on a given TCP socket were being performed
incorrectly. This fix alters parameter inputs to the MD5
lookup function tcp_md5_do_lookup, which is called by functions
tcp_md5_do_add and tcp_md5_do_del. Specifically, the change now
inputs the correct address and address family required to make
a proper lookup.
Signed-off-by: NAydin Arik <aydin.arik@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp_ipv4.c

@@ -1003,7 +1003,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_md5sig_info *md5sig;
 
-	key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
+	key = tcp_md5_do_lookup(sk, addr, family);
 	if (key) {
 		/* Pre-existing entry - just update that one. */
 		memcpy(key->key, newkey, newkeylen);
@@ -1048,7 +1048,7 @@ int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family)
 	struct tcp_md5sig_key *key;
 	struct tcp_md5sig_info *md5sig;
 
-	key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
+	key = tcp_md5_do_lookup(sk, addr, family);
 	if (!key)
 		return -ENOENT;
 	hlist_del_rcu(&key->node);