Commit 71df14b0 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso

netfilter: nf_tables: missing sanitization in data from userspace

Do not assume userspace always sends us NFT_DATA_VALUE for bitwise and
cmp expressions. Although NFT_DATA_VERDICT does not make any sense, it
is still possible to handcraft a netlink message using this incorrect
data type.
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent fa803605
......@@ -83,17 +83,26 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
if (d1.len != priv->len)
return -EINVAL;
if (d1.len != priv->len) {
err = -EINVAL;
goto err1;
}
err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
tb[NFTA_BITWISE_XOR]);
if (err < 0)
return err;
if (d2.len != priv->len)
return -EINVAL;
goto err1;
if (d2.len != priv->len) {
err = -EINVAL;
goto err2;
}
return 0;
err2:
nft_data_uninit(&priv->xor, d2.type);
err1:
nft_data_uninit(&priv->mask, d1.type);
return err;
}
static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
......
......@@ -201,10 +201,18 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
if (err < 0)
return ERR_PTR(err);
if (desc.type != NFT_DATA_VALUE) {
err = -EINVAL;
goto err1;
}
if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
return &nft_cmp_fast_ops;
else
return &nft_cmp_ops;
err1:
nft_data_uninit(&data, desc.type);
return ERR_PTR(-EINVAL);
}
struct nft_expr_type nft_cmp_type __read_mostly = {
......
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