netfilter: allow to turn off xtables compat layer

The compat layer needs to parse untrusted input (the ruleset)
to translate it to a 64bit compatible format.

We had a number of bugs in this department in the past, so allow users
to turn this feature off.

Add CONFIG_NETFILTER_XTABLES_COMPAT kconfig knob and make it default to y
to keep existing behaviour.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 9 insertions, 9 deletions

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index a52cc22f806a..07c6ad8f2a02 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -158,7 +158,7 @@ struct xt_match {
 
 	/* Called when entry of this type deleted. */
 	void (*destroy)(const struct xt_mtdtor_param *);
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	/* Called when userspace align differs from kernel space one */
 	void (*compat_from_user)(void *dst, const void *src);
 	int (*compat_to_user)(void __user *dst, const void *src);
@@ -169,7 +169,7 @@ struct xt_match {
 	const char *table;
 	unsigned int matchsize;
 	unsigned int usersize;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	unsigned int compatsize;
 #endif
 	unsigned int hooks;
@@ -199,7 +199,7 @@ struct xt_target {
 
 	/* Called when entry of this type deleted. */
 	void (*destroy)(const struct xt_tgdtor_param *);
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	/* Called when userspace align differs from kernel space one */
 	void (*compat_from_user)(void *dst, const void *src);
 	int (*compat_to_user)(void __user *dst, const void *src);
@@ -210,7 +210,7 @@ struct xt_target {
 	const char *table;
 	unsigned int targetsize;
 	unsigned int usersize;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	unsigned int compatsize;
 #endif
 	unsigned int hooks;
@@ -452,7 +452,7 @@ xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu)
 
 struct nf_hook_ops *xt_hook_ops_alloc(const struct xt_table *, nf_hookfn *);
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 #include <net/compat.h>
 
 struct compat_xt_entry_match {
@@ -533,5 +533,5 @@ int xt_compat_check_entry_offsets(const void *base, const char *elems,
 				  unsigned int target_offset,
 				  unsigned int next_offset);
 
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
 #endif /* _X_TABLES_H */
diff --git a/include/linux/netfilter_arp/arp_tables.h b/include/linux/netfilter_arp/arp_tables.h
index a0474b4e7782..2aab9612f6ab 100644
--- a/include/linux/netfilter_arp/arp_tables.h
+++ b/include/linux/netfilter_arp/arp_tables.h
@@ -59,7 +59,7 @@ extern unsigned int arpt_do_table(struct sk_buff *skb,
 				  const struct nf_hook_state *state,
 				  struct xt_table *table);
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 #include <net/compat.h>
 
 struct compat_arpt_entry {
diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index 0fdab3246ef5..8d09bfe850dc 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -67,7 +67,7 @@ extern unsigned int ipt_do_table(struct sk_buff *skb,
 				 const struct nf_hook_state *state,
 				 struct xt_table *table);
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 #include <net/compat.h>
 
 struct compat_ipt_entry {
diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h
index 11d0e725fe79..79e73fd7d965 100644
--- a/include/linux/netfilter_ipv6/ip6_tables.h
+++ b/include/linux/netfilter_ipv6/ip6_tables.h
@@ -33,7 +33,7 @@ extern unsigned int ip6t_do_table(struct sk_buff *skb,
 				  const struct nf_hook_state *state,
 				  struct xt_table *table);
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 #include <net/compat.h>
 
 struct compat_ip6t_entry {