xt_hashlimit: allocate a copy of name explicitly, don't rely on procfs guts

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net/netfilter/xt_hashlimit.c

@@ -107,6 +107,7 @@ struct xt_hashlimit_htable {
 
 	/* seq_file stuff */
 	struct proc_dir_entry *pde;
+	const char *name;
 	struct net *net;
 
 	struct hlist_head hash[0];	/* hashtable itself */
@@ -253,6 +254,11 @@ static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
 	hinfo->count = 0;
 	hinfo->family = family;
 	hinfo->rnd_initialized = false;
+	hinfo->name = kstrdup(minfo->name, GFP_KERNEL);
+	if (!hinfo->name) {
+		vfree(hinfo);
+		return -ENOMEM;
+	}
 	spin_lock_init(&hinfo->lock);
 
 	hinfo->pde = proc_create_data(minfo->name, 0,
@@ -260,6 +266,7 @@ static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
 		hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
 		&dl_file_ops, hinfo);
 	if (hinfo->pde == NULL) {
+		kfree(hinfo->name);
 		vfree(hinfo);
 		return -ENOMEM;
 	}
@@ -330,9 +337,10 @@ static void htable_destroy(struct xt_hashlimit_htable *hinfo)
 		parent = hashlimit_net->ip6t_hashlimit;
 
 	if(parent != NULL)
-		remove_proc_entry(hinfo->pde->name, parent);
+		remove_proc_entry(hinfo->name, parent);
 
 	htable_selective_cleanup(hinfo, select_all);
+	kfree(hinfo->name);
 	vfree(hinfo);
 }
 
@@ -344,7 +352,7 @@ static struct xt_hashlimit_htable *htable_find_get(struct net *net,
 	struct xt_hashlimit_htable *hinfo;
 
 	hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) {
-		if (!strcmp(name, hinfo->pde->name) &&
+		if (!strcmp(name, hinfo->name) &&
 		    hinfo->family == family) {
 			hinfo->use++;
 			return hinfo;
@@ -887,7 +895,7 @@ static void __net_exit hashlimit_proc_net_exit(struct net *net)
 		pde = hashlimit_net->ip6t_hashlimit;
 
 	hlist_for_each_entry(hinfo, &hashlimit_net->htables, node)
-		remove_proc_entry(hinfo->pde->name, pde);
+		remove_proc_entry(hinfo->name, pde);
 
 	hashlimit_net->ipt_hashlimit = NULL;
 	hashlimit_net->ip6t_hashlimit = NULL;