ipv6: check return value for dst_alloc

return value of dst_alloc must be checked before use
Signed-off-by: Madalin Bucur <madalin.bucur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/route.c

@@ -244,7 +244,9 @@ static inline struct rt6_info *ip6_dst_alloc(struct dst_ops *ops,
 {
 	struct rt6_info *rt = dst_alloc(ops, dev, 0, 0, flags);
 
-	memset(&rt->rt6i_table, 0, sizeof(*rt) - sizeof(struct dst_entry));
+	if (rt != NULL)
+		memset(&rt->rt6i_table, 0,
+			sizeof(*rt) - sizeof(struct dst_entry));
 
 	return rt;
 }