netfilter: nf_tables: Reject tables of unsupported family

commit f1082dd31f 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.

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>
This commit is contained in:
Phil Sutter 2022-02-16 15:55:38 +01:00 committed by Greg Kroah-Hartman
parent 0eb556b238
commit ab3a3aadb3

View file

@ -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,