netfilter: nf_tables: disallow updates of anonymous sets

Disallow updates of set timeout and garbage collection parameters for
anonymous sets.

Fixes: 123b99619c ("netfilter: nf_tables: honor set timeout and garbage collection updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -4963,6 +4963,9 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
 		if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
 			return -EOPNOTSUPP;
 
+		if (nft_set_is_anonymous(set))
+			return -EOPNOTSUPP;
+
 		err = nft_set_expr_alloc(&ctx, set, nla, exprs, &num_exprs, flags);
 		if (err < 0)
 			return err;