netfilter: nf_tables: allow up to 64 bytes in the set element data area

So far, the set elements could store up to 128-bits in the data area.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_tables.h

@@ -243,6 +243,10 @@ struct nft_set_elem {
 		u32		buf[NFT_DATA_VALUE_MAXLEN / sizeof(u32)];
 		struct nft_data	val;
 	} key_end;
+	union {
+		u32		buf[NFT_DATA_VALUE_MAXLEN / sizeof(u32)];
+		struct nft_data val;
+	} data;
 	void			*priv;
 };
 

net/netfilter/nf_tables_api.c

@@ -4669,6 +4669,25 @@ static int nft_setelem_parse_key(struct nft_ctx *ctx, struct nft_set *set,
 	return 0;
 }
 
+static int nft_setelem_parse_data(struct nft_ctx *ctx, struct nft_set *set,
+				  struct nft_data_desc *desc,
+				  struct nft_data *data,
+				  struct nlattr *attr)
+{
+	int err;
+
+	err = nft_data_init(ctx, data, NFT_DATA_VALUE_MAXLEN, desc, attr);
+	if (err < 0)
+		return err;
+
+	if (desc->type != NFT_DATA_VERDICT && desc->len != set->dlen) {
+		nft_data_release(data, desc->type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			    const struct nlattr *attr)
 {
@@ -4946,7 +4965,6 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	struct nft_expr *expr = NULL;
 	struct nft_userdata *udata;
 	struct nft_data_desc desc;
-	struct nft_data data;
 	enum nft_registers dreg;
 	struct nft_trans *trans;
 	u32 flags = 0;
@@ -5072,15 +5090,11 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	}
 
 	if (nla[NFTA_SET_ELEM_DATA] != NULL) {
-		err = nft_data_init(ctx, &data, sizeof(data), &desc,
-				    nla[NFTA_SET_ELEM_DATA]);
+		err = nft_setelem_parse_data(ctx, set, &desc, &elem.data.val,
+					     nla[NFTA_SET_ELEM_DATA]);
 		if (err < 0)
 			goto err_parse_key_end;
 
-		err = -EINVAL;
-		if (set->dtype != NFT_DATA_VERDICT && desc.len != set->dlen)
-			goto err_parse_data;
-
 		dreg = nft_type_to_reg(set->dtype);
 		list_for_each_entry(binding, &set->bindings, list) {
 			struct nft_ctx bind_ctx = {
@@ -5094,14 +5108,14 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 				continue;
 
 			err = nft_validate_register_store(&bind_ctx, dreg,
-							  &data,
+							  &elem.data.val,
 							  desc.type, desc.len);
 			if (err < 0)
 				goto err_parse_data;
 
 			if (desc.type == NFT_DATA_VERDICT &&
-			    (data.verdict.code == NFT_GOTO ||
-			     data.verdict.code == NFT_JUMP))
+			    (elem.data.val.verdict.code == NFT_GOTO ||
+			     elem.data.val.verdict.code == NFT_JUMP))
 				nft_validate_state_update(ctx->net,
 							  NFT_VALIDATE_NEED);
 		}
@@ -5123,7 +5137,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 
 	err = -ENOMEM;
 	elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data,
-				      elem.key_end.val.data, data.data,
+				      elem.key_end.val.data, elem.data.val.data,
 				      timeout, expiration, GFP_KERNEL);
 	if (elem.priv == NULL)
 		goto err_parse_data;
@@ -5201,7 +5215,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	nf_tables_set_elem_destroy(ctx, set, elem.priv);
 err_parse_data:
 	if (nla[NFTA_SET_ELEM_DATA] != NULL)
-		nft_data_release(&data, desc.type);
+		nft_data_release(&elem.data.val, desc.type);
 err_parse_key_end:
 	nft_data_release(&elem.key_end.val, NFT_DATA_VALUE);
 err_parse_key: