This is a note to let you know that I've just added the patch titled
netfilter: nf_tables: Reject tables of unsupported family
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-nf_tables-reject-tables-of-unsupported-family.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f1082dd31fe461d482d69da2a8eccfeb7bf07ac2 Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@xxxxxx>
Date: Wed, 16 Feb 2022 15:55:38 +0100
Subject: netfilter: nf_tables: Reject tables of unsupported family
From: Phil Sutter <phil@xxxxxx>
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.
Signed-off-by: Phil Sutter <phil@xxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -893,6 +893,30 @@ static int nft_chain_hash_cmp(struct rha
return strcmp(chain->name, 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 net *net, struct sock *nlsk,
struct sk_buff *skb, const struct nlmsghdr *nlh,
const struct nlattr * const nla[],
@@ -908,6 +932,9 @@ static int nf_tables_newtable(struct net
struct nft_ctx ctx;
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);
Patches currently in stable-queue which might be from phil@xxxxxx are
queue-4.19/netfilter-nf_tables-reject-tables-of-unsupported-family.patch
