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 <[e-mail]>
Signed-off-by: Joel Granados <[e-mail]>
Signed-off-by: Luis Chamberlain <[e-mail]>

net/bridge/br_netfilter_hooks.c

···
 
 	br_netfilter_sysctl_default(brnet);
 
-	brnet->ctl_hdr = register_net_sysctl(net, "net/bridge", table);
+	brnet->ctl_hdr = register_net_sysctl_sz(net, "net/bridge", table,
+						ARRAY_SIZE(brnf_table));
 	if (!brnet->ctl_hdr) {
 		if (!net_eq(net, &init_net))
 			kfree(table);

net/ipv6/netfilter/nf_conntrack_reasm.c

···
 	table[2].data	= &nf_frag->fqdir->high_thresh;
 	table[2].extra1	= &nf_frag->fqdir->low_thresh;
 
-	hdr = register_net_sysctl(net, "net/netfilter", table);
+	hdr = register_net_sysctl_sz(net, "net/netfilter", table,
+				     ARRAY_SIZE(nf_ct_frag6_sysctl_table));
 	if (hdr == NULL)
 		goto err_reg;
 

net/netfilter/ipvs/ip_vs_ctl.c

···
 	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);
···
 			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 */
···
 #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;

net/netfilter/ipvs/ip_vs_lblc.c

···
 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;
···
 			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);

net/netfilter/ipvs/ip_vs_lblcr.c

···
 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;
···
 			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);

net/netfilter/nf_conntrack_standalone.c

···
 		table[NF_SYSCTL_CT_BUCKETS].mode = 0444;
 	}
 
-	cnet->sysctl_header = register_net_sysctl(net, "net/netfilter", table);
+	cnet->sysctl_header = register_net_sysctl_sz(net, "net/netfilter",
+						     table,
+						     ARRAY_SIZE(nf_ct_sysctl_table));
 	if (!cnet->sysctl_header)
 		goto out_unregister_netfilter;
 

net/netfilter/nf_log.c

···
 	for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
 		table[i].extra2 = net;
 
-	net->nf.nf_log_dir_header = register_net_sysctl(net,
-						"net/netfilter/nf_log",
-						table);
+	net->nf.nf_log_dir_header = register_net_sysctl_sz(net,
+							   "net/netfilter/nf_log",
+							   table,
+							   ARRAY_SIZE(nf_log_sysctl_table));
 	if (!net->nf.nf_log_dir_header)
 		goto err_reg;