netfilter: nf_tables: fix dumping with large number of sets

If not table name is specified, the dumping of the existing sets
may be incomplete with a sufficiently large number of sets and
tables. This patch fixes missing reset of the cursors after
finding the location of the last object that has been included
in the previous multi-part message.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -2098,17 +2098,21 @@ static int nf_tables_dump_sets_all(struct nft_ctx *ctx, struct sk_buff *skb,
 				   struct netlink_callback *cb)
 {
 	const struct nft_set *set;
-	unsigned int idx = 0, s_idx = cb->args[0];
+	unsigned int idx, s_idx = cb->args[0];
 	struct nft_table *table, *cur_table = (struct nft_table *)cb->args[2];
 
 	if (cb->args[1])
 		return skb->len;
 
 	list_for_each_entry(table, &ctx->afi->tables, list) {
-		if (cur_table && cur_table != table)
+		if (cur_table) {
+			if (cur_table != table)
 				continue;
 
+			cur_table = NULL;
+		}
 		ctx->table = table;
+		idx = 0;
 		list_for_each_entry(set, &ctx->table->sets, list) {
 			if (idx < s_idx)
 				goto cont;