netfilter: fix two recent sysctl problems

Starting with 9043476f726802f4b00c96d0c4f418dde48d1304 ("[PATCH]
sanitize proc_sysctl") we have two netfilter releated problems:

- WARNING: at kernel/sysctl.c:1966 unregister_sysctl_table+0xcc/0x103(),
caused by wrong order of ini/fini calls

- net.netfilter is duplicated and has truncated set of records

Thanks to very useful guidelines from Al Viro, this patch fixes both
of them.

Signed-off-by: Krzysztof Piotr Oledzki <[e-mail]>
Acked-by: Al Viro <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/netfilter/nf_conntrack_core.c

···
 	nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_vmalloc,
 			     nf_conntrack_htable_size);
 
-	nf_conntrack_proto_fini();
-	nf_conntrack_helper_fini();
-	nf_conntrack_expect_fini();
 	nf_conntrack_acct_fini();
+	nf_conntrack_expect_fini();
+	nf_conntrack_helper_fini();
+	nf_conntrack_proto_fini();
 }
 
 struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced)

net/netfilter/nf_conntrack_standalone.c

···
 static int log_invalid_proto_max = 255;
 
 static struct ctl_table_header *nf_ct_sysctl_header;
+static struct ctl_table_header *nf_ct_netfilter_header;
 
 static ctl_table nf_ct_sysctl_table[] = {
 	{
···
 
 static ctl_table nf_ct_netfilter_table[] = {
 	{
-		.ctl_name	= NET_NETFILTER,
-		.procname	= "netfilter",
-		.mode		= 0555,
-		.child		= nf_ct_sysctl_table,
-	},
-	{
 		.ctl_name	= NET_NF_CONNTRACK_MAX,
 		.procname	= "nf_conntrack_max",
 		.data		= &nf_conntrack_max,
···
 
 static int nf_conntrack_standalone_init_sysctl(void)
 {
-	nf_ct_sysctl_header =
+	nf_ct_netfilter_header =
 		register_sysctl_paths(nf_ct_path, nf_ct_netfilter_table);
-	if (nf_ct_sysctl_header == NULL) {
-		printk("nf_conntrack: can't register to sysctl.\n");
-		return -ENOMEM;
-	}
+	if (!nf_ct_netfilter_header)
+		goto out;
+
+	nf_ct_sysctl_header =
+		 register_sysctl_paths(nf_net_netfilter_sysctl_path,
+					nf_ct_sysctl_table);
+	if (!nf_ct_sysctl_header)
+		goto out_unregister_netfilter;
+
 	return 0;
 
+out_unregister_netfilter:
+	unregister_sysctl_table(nf_ct_netfilter_header);
+out:
+	printk("nf_conntrack: can't register to sysctl.\n");
+	return -ENOMEM;
 }
 
 static void nf_conntrack_standalone_fini_sysctl(void)
 {
+	unregister_sysctl_table(nf_ct_netfilter_header);
 	unregister_sysctl_table(nf_ct_sysctl_header);
 }
 #else