Commit d694b754 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

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 3e48be05 ("netlink: add attribute range
validation to policy").

Fixes: 0ca743a5 ("netfilter: nf_tables: add compatibility layer for x_tables")
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 292781c3

net/netfilter/nft_compat.c

+7 −1
Original line number Diff line number Diff line
@@ -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;

}