netfilter: nf_tables: Reject tables of unsupported family

commit f1082dd31fe461d482d69da2a8eccfeb7bf07ac2 upstream.

An nftables family is merely a hollow container, its family just a
number and such not reliant on compile-time options other than nftables
support itself. Add an artificial check so attempts at using a family
the kernel can't support fail as early as possible. This helps user
space detect kernels which lack e.g. NFPROTO_INET.

BUG=b/321923857
TEST=None
RELEASE_NOTE=Fixed CVE-2023-6040 in the linux kernel.

cos-patch: security-high
Change-Id: I730b947d2d8e248a7ad1fed28e55cbf154118fb3
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/64188
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>

net/netfilter/nf_tables_api.c

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3ee0f63..3556818 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1247,6 +1247,30 @@ static int nft_objname_hash_cmp(struct rhashtable_compare_arg *arg,
 	return strcmp(obj->key.name, k->name);
 }
 
+static bool nft_supported_family(u8 family)
+{
+	return false
+#ifdef CONFIG_NF_TABLES_INET
+		|| family == NFPROTO_INET
+#endif
+#ifdef CONFIG_NF_TABLES_IPV4
+		|| family == NFPROTO_IPV4
+#endif
+#ifdef CONFIG_NF_TABLES_ARP
+		|| family == NFPROTO_ARP
+#endif
+#ifdef CONFIG_NF_TABLES_NETDEV
+		|| family == NFPROTO_NETDEV
+#endif
+#if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE)
+		|| family == NFPROTO_BRIDGE
+#endif
+#ifdef CONFIG_NF_TABLES_IPV6
+		|| family == NFPROTO_IPV6
+#endif
+		;
+}
+
 static int nf_tables_newtable(struct sk_buff *skb, const struct nfnl_info *info,
 			      const struct nlattr * const nla[])
 {
@@ -1261,6 +1285,9 @@ static int nf_tables_newtable(struct sk_buff *skb, const struct nfnl_info *info,
 	u32 flags = 0;
 	int err;
 
+	if (!nft_supported_family(family))
+		return -EOPNOTSUPP;
+
 	lockdep_assert_held(&nft_net->commit_mutex);
 	attr = nla[NFTA_TABLE_NAME];
 	table = nft_table_lookup(net, attr, family, genmask,