From e17f2dbcf08c464fe0e227f994033b6d69f68842 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcin=20Wcis=C5=82o?= Date: Fri, 25 Jul 2025 20:15:54 +0200 Subject: [PATCH] netfilter: nf_tables: Reject tables of unsupported family MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit jira VULN-8164 cve CVE-2023-6040 commit-author Phil Sutter commit f1082dd31fe461d482d69da2a8eccfeb7bf07ac2 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. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso (cherry picked from commit f1082dd31fe461d482d69da2a8eccfeb7bf07ac2) Signed-off-by: Marcin Wcisło --- net/netfilter/nf_tables_api.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 015f13c824667..88dd8669336d0 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1164,6 +1164,30 @@ 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[]) { @@ -1178,6 +1202,9 @@ 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,