tipc: Return non-zero value from tipc_udp_addr2str() on error

tipc_udp_addr2str() should return non-zero value if the UDP media
address is invalid. Otherwise, a buffer overflow access can occur in
tipc_media_addr_printf(). Fix this by returning 1 on an invalid UDP
media address.

Fixes: d0f91938 ("tipc: add ip/udp media type")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Tung Nguyen <tung.q.nguyen@endava.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/udp_media.c

@@ -135,8 +135,11 @@ static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
 		snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port));
 	else if (ntohs(ua->proto) == ETH_P_IPV6)
 		snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port));
-	else
+	else {
 		pr_err("Invalid UDP media address\n");
+		return 1;
+	}
+
 	return 0;
 }