netfilter: Use kmemdup_array instead of kmemdup for multiple allocation

When we are allocating an array, using kmemdup_array() to take care about
multiplication and possible overflows.

Also it makes auditing the code easier.

Signed-off-by: Yan Zhen <[e-mail]>
Reviewed-by: Florian Westphal <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

net/bridge/netfilter/ebtables.c

···
 		goto free_unlock;
 	}
 
-	ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+	ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
 	if (!ops) {
 		ret = -ENOMEM;
 		if (newinfo->nentries)

net/ipv4/netfilter/arp_tables.c

···
 		goto out_free;
 	}
 
-	ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+	ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
 	if (!ops) {
 		ret = -ENOMEM;
 		goto out_free;

net/ipv4/netfilter/ip_tables.c

···
 		goto out_free;
 	}
 
-	ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+	ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
 	if (!ops) {
 		ret = -ENOMEM;
 		goto out_free;

net/ipv6/netfilter/ip6_tables.c

···
 		goto out_free;
 	}
 
-	ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL);
+	ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
 	if (!ops) {
 		ret = -ENOMEM;
 		goto out_free;

net/netfilter/nf_nat_core.c

···
 	if (!nat_proto_net->nat_hook_ops) {
 		WARN_ON(nat_proto_net->users != 0);
 
-		nat_ops = kmemdup(orig_nat_ops, sizeof(*orig_nat_ops) * ops_count, GFP_KERNEL);
+		nat_ops = kmemdup_array(orig_nat_ops, ops_count, sizeof(*orig_nat_ops), GFP_KERNEL);
 		if (!nat_ops) {
 			mutex_unlock(&nf_nat_proto_mutex);
 			return -ENOMEM;