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>

3 files changed, 20 insertions, 20 deletions

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index b1bb6a7e2dd7..cf20316094d0 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -713,7 +713,7 @@ static int copy_entries_to_user(unsigned int total_size,
 	return ret;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 static void compat_standard_from_user(void *dst, const void *src)
 {
 	int v = *(compat_int_t *)src;
@@ -800,7 +800,7 @@ static int get_info(struct net *net, void __user *user, const int *len)
 		return -EFAULT;
 
 	name[XT_TABLE_MAXNAMELEN-1] = '\0';
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	if (in_compat_syscall())
 		xt_compat_lock(NFPROTO_ARP);
 #endif
@@ -808,7 +808,7 @@ static int get_info(struct net *net, void __user *user, const int *len)
 	if (!IS_ERR(t)) {
 		struct arpt_getinfo info;
 		const struct xt_table_info *private = t->private;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		struct xt_table_info tmp;
 
 		if (in_compat_syscall()) {
@@ -835,7 +835,7 @@ static int get_info(struct net *net, void __user *user, const int *len)
 		module_put(t->me);
 	} else
 		ret = PTR_ERR(t);
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	if (in_compat_syscall())
 		xt_compat_unlock(NFPROTO_ARP);
 #endif
@@ -1044,7 +1044,7 @@ static int do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
 	return ret;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 struct compat_arpt_replace {
 	char				name[XT_TABLE_MAXNAMELEN];
 	u32				valid_hooks;
@@ -1412,7 +1412,7 @@ static int do_arpt_set_ctl(struct sock *sk, int cmd, sockptr_t arg,
 
 	switch (cmd) {
 	case ARPT_SO_SET_REPLACE:
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		if (in_compat_syscall())
 			ret = compat_do_replace(sock_net(sk), arg, len);
 		else
@@ -1444,7 +1444,7 @@ static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len
 		break;
 
 	case ARPT_SO_GET_ENTRIES:
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		if (in_compat_syscall())
 			ret = compat_get_entries(sock_net(sk), user, len);
 		else
@@ -1580,7 +1580,7 @@ static struct xt_target arpt_builtin_tg[] __read_mostly = {
 		.name             = XT_STANDARD_TARGET,
 		.targetsize       = sizeof(int),
 		.family           = NFPROTO_ARP,
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		.compatsize       = sizeof(compat_int_t),
 		.compat_from_user = compat_standard_from_user,
 		.compat_to_user   = compat_standard_to_user,
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index d6caaed5dd45..13acb687c19a 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -868,7 +868,7 @@ copy_entries_to_user(unsigned int total_size,
 	return ret;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 static void compat_standard_from_user(void *dst, const void *src)
 {
 	int v = *(compat_int_t *)src;
@@ -957,7 +957,7 @@ static int get_info(struct net *net, void __user *user, const int *len)
 		return -EFAULT;
 
 	name[XT_TABLE_MAXNAMELEN-1] = '\0';
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	if (in_compat_syscall())
 		xt_compat_lock(AF_INET);
 #endif
@@ -965,7 +965,7 @@ static int get_info(struct net *net, void __user *user, const int *len)
 	if (!IS_ERR(t)) {
 		struct ipt_getinfo info;
 		const struct xt_table_info *private = t->private;
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		struct xt_table_info tmp;
 
 		if (in_compat_syscall()) {
@@ -993,7 +993,7 @@ static int get_info(struct net *net, void __user *user, const int *len)
 		module_put(t->me);
 	} else
 		ret = PTR_ERR(t);
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	if (in_compat_syscall())
 		xt_compat_unlock(AF_INET);
 #endif
@@ -1199,7 +1199,7 @@ do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
 	return ret;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 struct compat_ipt_replace {
 	char			name[XT_TABLE_MAXNAMELEN];
 	u32			valid_hooks;
@@ -1621,7 +1621,7 @@ do_ipt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len)
 
 	switch (cmd) {
 	case IPT_SO_SET_REPLACE:
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		if (in_compat_syscall())
 			ret = compat_do_replace(sock_net(sk), arg, len);
 		else
@@ -1654,7 +1654,7 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 		break;
 
 	case IPT_SO_GET_ENTRIES:
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		if (in_compat_syscall())
 			ret = compat_get_entries(sock_net(sk), user, len);
 		else
@@ -1846,7 +1846,7 @@ static struct xt_target ipt_builtin_tg[] __read_mostly = {
 		.name             = XT_STANDARD_TARGET,
 		.targetsize       = sizeof(int),
 		.family           = NFPROTO_IPV4,
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 		.compatsize       = sizeof(compat_int_t),
 		.compat_from_user = compat_standard_from_user,
 		.compat_to_user   = compat_standard_to_user,
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index a8b980ad11d4..8f7ca67475b7 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -541,7 +541,7 @@ static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
 	nf_ct_netns_put(par->net, par->family);
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 struct compat_ipt_clusterip_tgt_info
 {
 	u_int32_t	flags;
@@ -553,7 +553,7 @@ struct compat_ipt_clusterip_tgt_info
 	u_int32_t	hash_initval;
 	compat_uptr_t	config;
 };
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
 
 static struct xt_target clusterip_tg_reg __read_mostly = {
 	.name		= "CLUSTERIP",
@@ -563,9 +563,9 @@ static struct xt_target clusterip_tg_reg __read_mostly = {
 	.destroy	= clusterip_tg_destroy,
 	.targetsize	= sizeof(struct ipt_clusterip_tgt_info),
 	.usersize	= offsetof(struct ipt_clusterip_tgt_info, config),
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
 	.compatsize	= sizeof(struct compat_ipt_clusterip_tgt_info),
-#endif /* CONFIG_COMPAT */
+#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
 	.me		= THIS_MODULE
 };