netfilter: nf_tables: validate NFT_DATA_VALUE after nft_data_init()

Userspace might bogusly sent NFT_DATA_VERDICT in several netlink
attributes that assume NFT_DATA_VALUE. Moreover, make sure that error
path invokes nft_data_release() to decrement the reference count on the
chain object.

Fixes: 96518518cc41 ("netfilter: add nftables")
Fixes: 0f3cd9b36977 ("netfilter: nf_tables: add range expression")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0db2784..72a7816 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4519,8 +4519,10 @@ static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
                return err;
 
        err = -EINVAL;
-       if (desc.type != NFT_DATA_VALUE || desc.len != set->klen)
+       if (desc.type != NFT_DATA_VALUE || desc.len != set->klen) {
+               nft_data_release(&elem.key.val, desc.type);
                return err;
+       }
 
        priv = set->ops->get(ctx->net, set, &elem, flags);
        if (IS_ERR(priv))

diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c
index 02afa75..10e9d50 100644 (file)
--- a/net/netfilter/nft_bitwise.c
+++ b/net/netfilter/nft_bitwise.c
@@ -80,7 +80,7 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
                            tb[NFTA_BITWISE_MASK]);
        if (err < 0)
                return err;
-       if (d1.len != priv->len) {
+       if (d1.type != NFT_DATA_VALUE || d1.len != priv->len) {
                err = -EINVAL;
                goto err1;
        }
@@ -89,7 +89,7 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
                            tb[NFTA_BITWISE_XOR]);
        if (err < 0)
                goto err1;
-       if (d2.len != priv->len) {
+       if (d2.type != NFT_DATA_VALUE || d2.len != priv->len) {
                err = -EINVAL;
                goto err2;
        }

diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index b809206..8a28c12 100644 (file)
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -81,6 +81,12 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
        if (err < 0)
                return err;
 
+       if (desc.type != NFT_DATA_VALUE) {
+               err = -EINVAL;
+               nft_data_release(&priv->data, desc.type);
+               return err;
+       }
+
        priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
        err = nft_validate_register_load(priv->sreg, desc.len);
        if (err < 0)

diff --git a/net/netfilter/nft_range.c b/net/netfilter/nft_range.c
index 4701fa8..89efcc5 100644 (file)
--- a/net/netfilter/nft_range.c
+++ b/net/netfilter/nft_range.c
@@ -66,11 +66,21 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr
        if (err < 0)
                return err;
 
+       if (desc_from.type != NFT_DATA_VALUE) {
+               err = -EINVAL;
+               goto err1;
+       }
+
        err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to),
                            &desc_to, tb[NFTA_RANGE_TO_DATA]);
        if (err < 0)
                goto err1;
 
+       if (desc_to.type != NFT_DATA_VALUE) {
+               err = -EINVAL;
+               goto err2;
+       }
+
        if (desc_from.len != desc_to.len) {
                err = -EINVAL;
                goto err2;