netfilter: nft_compat: restrict match/target protocol to u16

xt_check_{match,target} expects u16, but NFTA_RULE_COMPAT_PROTO is u32.

NLA_POLICY_MAX(NLA_BE32, 65535) cannot be used because .max in
nla_policy is s16, see 3e48be05f3 ("netlink: add attribute range
validation to policy").

Fixes: 0ca743a559 ("netfilter: nf_tables: add compatibility layer for x_tables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2024-02-02 00:05:23 +01:00
parent 292781c3c5
commit d694b75489

View File

@ -200,6 +200,7 @@ static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1]
static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
{
struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
u32 l4proto;
u32 flags;
int err;
@ -218,7 +219,12 @@ static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
if (flags & NFT_RULE_COMPAT_F_INV)
*inv = true;
*proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
l4proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
if (l4proto > U16_MAX)
return -EINVAL;
*proto = l4proto;
return 0;
}