netfilter: nf_nat: fix out-of-bounds access in address selection

include/linux/jhash.h:138:16: warning: array subscript is above array bounds
[jhash2() expects the number of u32 in the key]
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_nat_core.c

@@ -255,7 +255,7 @@ find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple,
 	 * client coming from the same IP (some Internet Banking sites
 	 * like this), even across reboots.
 	 */
-	j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3),
+	j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
 		   range->flags & NF_NAT_RANGE_PERSISTENT ?
 			0 : (__force u32)tuple->dst.u3.all[max] ^ zone);