netfilter: Update to register_net_sysctl_sz

Move from register_net_sysctl to register_net_sysctl_sz for all the
netfilter related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

3 files changed, 20 insertions, 8 deletions

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 62606fb44d02..8d69e4c2d822 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -4266,6 +4266,7 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 	struct net *net = ipvs->net;
 	struct ctl_table *tbl;
 	int idx, ret;
+	size_t ctl_table_size = ARRAY_SIZE(vs_vars);
 
 	atomic_set(&ipvs->dropentry, 0);
 	spin_lock_init(&ipvs->dropentry_lock);
@@ -4282,8 +4283,10 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 			return -ENOMEM;
 
 		/* Don't export sysctls to unprivileged users */
-		if (net->user_ns != &init_user_ns)
+		if (net->user_ns != &init_user_ns) {
 			tbl[0].procname = NULL;
+			ctl_table_size = 0;
+		}
 	} else
 		tbl = vs_vars;
 	/* Initialize sysctl defaults */
@@ -4353,7 +4356,8 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 #endif
 
 	ret = -ENOMEM;
-	ipvs->sysctl_hdr = register_net_sysctl(net, "net/ipv4/vs", tbl);
+	ipvs->sysctl_hdr = register_net_sysctl_sz(net, "net/ipv4/vs", tbl,
+						  ctl_table_size);
 	if (!ipvs->sysctl_hdr)
 		goto err;
 	ipvs->sysctl_tbl = tbl;
diff --git a/net/netfilter/ipvs/ip_vs_lblc.c b/net/netfilter/ipvs/ip_vs_lblc.c
index 1b87214d385e..cf78ba4ce5ff 100644
--- a/net/netfilter/ipvs/ip_vs_lblc.c
+++ b/net/netfilter/ipvs/ip_vs_lblc.c
@@ -550,6 +550,7 @@ static struct ip_vs_scheduler ip_vs_lblc_scheduler = {
 static int __net_init __ip_vs_lblc_init(struct net *net)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
+	size_t vars_table_size = ARRAY_SIZE(vs_vars_table);
 
 	if (!ipvs)
 		return -ENOENT;
@@ -562,16 +563,19 @@ static int __net_init __ip_vs_lblc_init(struct net *net)
 			return -ENOMEM;
 
 		/* Don't export sysctls to unprivileged users */
-		if (net->user_ns != &init_user_ns)
+		if (net->user_ns != &init_user_ns) {
 			ipvs->lblc_ctl_table[0].procname = NULL;
+			vars_table_size = 0;
+		}
 
 	} else
 		ipvs->lblc_ctl_table = vs_vars_table;
 	ipvs->sysctl_lblc_expiration = DEFAULT_EXPIRATION;
 	ipvs->lblc_ctl_table[0].data = &ipvs->sysctl_lblc_expiration;
 
-	ipvs->lblc_ctl_header =
-		register_net_sysctl(net, "net/ipv4/vs", ipvs->lblc_ctl_table);
+	ipvs->lblc_ctl_header = register_net_sysctl_sz(net, "net/ipv4/vs",
+						       ipvs->lblc_ctl_table,
+						       vars_table_size);
 	if (!ipvs->lblc_ctl_header) {
 		if (!net_eq(net, &init_net))
 			kfree(ipvs->lblc_ctl_table);
diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c
index ad8f5fea6d3a..9eddf118b40e 100644
--- a/net/netfilter/ipvs/ip_vs_lblcr.c
+++ b/net/netfilter/ipvs/ip_vs_lblcr.c
@@ -736,6 +736,7 @@ static struct ip_vs_scheduler ip_vs_lblcr_scheduler =
 static int __net_init __ip_vs_lblcr_init(struct net *net)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
+	size_t vars_table_size = ARRAY_SIZE(vs_vars_table);
 
 	if (!ipvs)
 		return -ENOENT;
@@ -748,15 +749,18 @@ static int __net_init __ip_vs_lblcr_init(struct net *net)
 			return -ENOMEM;
 
 		/* Don't export sysctls to unprivileged users */
-		if (net->user_ns != &init_user_ns)
+		if (net->user_ns != &init_user_ns) {
 			ipvs->lblcr_ctl_table[0].procname = NULL;
+			vars_table_size = 0;
+		}
 	} else
 		ipvs->lblcr_ctl_table = vs_vars_table;
 	ipvs->sysctl_lblcr_expiration = DEFAULT_EXPIRATION;
 	ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration;
 
-	ipvs->lblcr_ctl_header =
-		register_net_sysctl(net, "net/ipv4/vs", ipvs->lblcr_ctl_table);
+	ipvs->lblcr_ctl_header = register_net_sysctl_sz(net, "net/ipv4/vs",
+							ipvs->lblcr_ctl_table,
+							vars_table_size);
 	if (!ipvs->lblcr_ctl_header) {
 		if (!net_eq(net, &init_net))
 			kfree(ipvs->lblcr_ctl_table);