netfilter: nft_range: validate operation netlink attribute

Use nft_parse_u32_check() to make sure we don't get a value over the
unsigned 8-bit integer. Moreover, make sure this value doesn't go over
the two supported range comparison modes.

Fixes: 9286c2eb1fda ("netfilter: nft_range: validate operation netlink attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2016-10-13 08:42:17 +02:00
parent 21a9e0f156
commit ccca6607c5

View file

@ -59,6 +59,7 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr
struct nft_range_expr *priv = nft_expr_priv(expr);
struct nft_data_desc desc_from, desc_to;
int err;
u32 op;
err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from),
&desc_from, tb[NFTA_RANGE_FROM_DATA]);
@ -80,7 +81,20 @@ static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr
if (err < 0)
goto err2;
priv->op = ntohl(nla_get_be32(tb[NFTA_RANGE_OP]));
err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op);
if (err < 0)
goto err2;
switch (op) {
case NFT_RANGE_EQ:
case NFT_RANGE_NEQ:
break;
default:
err = -EINVAL;
goto err2;
}
priv->op = op;
priv->len = desc_from.len;
return 0;
err2: