[PATCH 6.1 16/71] netfilter: nft_ct: fix l3num expectations with inet pseudo family

Sasha Levin
2024-03-13T16:40:19Z

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 99993789966a6eb4f1295193dc543686899892d3 ]

Following is rejected but should be allowed:

table inet t {
ct expectation exp1 {
[..]
l3proto ip

Valid combos are:
table ip t, l3proto ip
table ip6 t, l3proto ip6
table inet t, l3proto ip OR l3proto ip6

Disallow inet pseudeo family, the l3num must be a on-wire protocol known
to conntrack.

Retain NFPROTO_INET case to make it clear its rejected
intentionally rather as oversight.

Fixes: 8059918a1377 ("netfilter: nft_ct: sanitize layer 3 and 4 protocol number in custom expectations")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_ct.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 8df7564f0611e..2bfe3cdfbd581 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -1237,14 +1237,13 @@ static int nft_ct_expect_obj_init(const struct nft_ctx *ctx,
switch (priv->l3num) {
case NFPROTO_IPV4:
case NFPROTO_IPV6:
- if (priv->l3num != ctx->family)
- return -EINVAL;
+ if (priv->l3num == ctx->family || ctx->family == NFPROTO_INET)
+ break;

- fallthrough;
- case NFPROTO_INET:
- break;
+ return -EINVAL;
+ case NFPROTO_INET: /* tuple.src.l3num supports NFPROTO_IPV4/6 only */
default:
- return -EOPNOTSUPP;
+ return -EAFNOSUPPORT;
}

priv->l4proto = nla_get_u8(tb[NFTA_CT_EXPECT_L4PROTO]);
--
2.43.0