netfilter: nft_ct: sanitize layer 3 and 4 protocol number in custom expectations

- Disallow families other than NFPROTO_{IPV4,IPV6,INET}.
- Disallow layer 4 protocol with no ports, since destination port is a
  mandatory attribute for this object.

Fixes: 857b46027d ("netfilter: nft_ct: add ct expectations support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2024-01-29 13:12:33 +01:00
parent 259eb32971
commit 8059918a13

View File

@ -1250,7 +1250,31 @@ static int nft_ct_expect_obj_init(const struct nft_ctx *ctx,
if (tb[NFTA_CT_EXPECT_L3PROTO])
priv->l3num = ntohs(nla_get_be16(tb[NFTA_CT_EXPECT_L3PROTO]));
switch (priv->l3num) {
case NFPROTO_IPV4:
case NFPROTO_IPV6:
if (priv->l3num != ctx->family)
return -EINVAL;
fallthrough;
case NFPROTO_INET:
break;
default:
return -EOPNOTSUPP;
}
priv->l4proto = nla_get_u8(tb[NFTA_CT_EXPECT_L4PROTO]);
switch (priv->l4proto) {
case IPPROTO_TCP:
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
case IPPROTO_DCCP:
case IPPROTO_SCTP:
break;
default:
return -EOPNOTSUPP;
}
priv->dport = nla_get_be16(tb[NFTA_CT_EXPECT_DPORT]);
priv->timeout = nla_get_u32(tb[NFTA_CT_EXPECT_TIMEOUT]);
priv->size = nla_get_u8(tb[NFTA_CT_EXPECT_SIZE]);