Merge branch 'appletalk-small-cleanup-and-bugfix'

Yue Haibing says:

====================
appletalk: small cleanup and bugfix

v2:
- Add cover letter log

This patch series mainly fix a use-after-free bug in atalk_proc_exit.
patch 1 use remove_proc_subtree helper to simplify atalk_proc fs code,
also some other cleanup.
patch 2 add proper error cleanup path in atalk_init to fix the issue, which
based on the patch 1 because of the change of atalk_proc_exit context.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/atalk.h

@@ -158,7 +158,7 @@ extern int sysctl_aarp_retransmit_limit;
 extern int sysctl_aarp_resolve_time;
 
 #ifdef CONFIG_SYSCTL
-extern void atalk_register_sysctl(void);
+extern int atalk_register_sysctl(void);
 extern void atalk_unregister_sysctl(void);
 #else
 #define atalk_register_sysctl()		do { } while(0)

net/appletalk/atalk_proc.c

@@ -210,56 +210,34 @@ static const struct seq_operations atalk_seq_socket_ops = {
 	.show   = atalk_seq_socket_show,
 };
 
-static struct proc_dir_entry *atalk_proc_dir;
-
 int __init atalk_proc_init(void)
 {
-	struct proc_dir_entry *p;
-	int rc = -ENOMEM;
+	if (!proc_mkdir("atalk", init_net.proc_net))
+		return -ENOMEM;
 
-	atalk_proc_dir = proc_mkdir("atalk", init_net.proc_net);
-	if (!atalk_proc_dir)
+	if (!proc_create_seq("atalk/interface", 0444, init_net.proc_net,
+			    &atalk_seq_interface_ops))
 		goto out;
 
-	p = proc_create_seq("interface", 0444, atalk_proc_dir,
-			&atalk_seq_interface_ops);
-	if (!p)
-		goto out_interface;
-
-	p = proc_create_seq("route", 0444, atalk_proc_dir,
-			&atalk_seq_route_ops);
-	if (!p)
-		goto out_route;
+	if (!proc_create_seq("atalk/route", 0444, init_net.proc_net,
+			    &atalk_seq_route_ops))
+		goto out;
 
-	p = proc_create_seq("socket", 0444, atalk_proc_dir,
-			&atalk_seq_socket_ops);
-	if (!p)
-		goto out_socket;
+	if (!proc_create_seq("atalk/socket", 0444, init_net.proc_net,
+			    &atalk_seq_socket_ops))
+		goto out;
 
-	p = proc_create_seq_private("arp", 0444, atalk_proc_dir, &aarp_seq_ops,
-			sizeof(struct aarp_iter_state), NULL);
-	if (!p)
-		goto out_arp;
+	if (!proc_create_seq_private("atalk/arp", 0444, init_net.proc_net,
+				     &aarp_seq_ops,
+				     sizeof(struct aarp_iter_state), NULL))
+		goto out;
 
-	rc = 0;
 out:
-	return rc;
-out_arp:
-	remove_proc_entry("socket", atalk_proc_dir);
-out_socket:
-	remove_proc_entry("route", atalk_proc_dir);
-out_route:
-	remove_proc_entry("interface", atalk_proc_dir);
-out_interface:
-	remove_proc_entry("atalk", init_net.proc_net);
-	goto out;
+	remove_proc_subtree("atalk", init_net.proc_net);
+	return -ENOMEM;
 }
 
-void __exit atalk_proc_exit(void)
+void atalk_proc_exit(void)
 {
-	remove_proc_entry("interface", atalk_proc_dir);
-	remove_proc_entry("route", atalk_proc_dir);
-	remove_proc_entry("socket", atalk_proc_dir);
-	remove_proc_entry("arp", atalk_proc_dir);
-	remove_proc_entry("atalk", init_net.proc_net);
+	remove_proc_subtree("atalk", init_net.proc_net);
 }

net/appletalk/ddp.c

@@ -1910,12 +1910,16 @@ static const char atalk_err_snap[] __initconst =
 /* Called by proto.c on kernel start up */
 static int __init atalk_init(void)
 {
-	int rc = proto_register(&ddp_proto, 0);
+	int rc;
 
-	if (rc != 0)
+	rc = proto_register(&ddp_proto, 0);
+	if (rc)
 		goto out;
 
-	(void)sock_register(&atalk_family_ops);
+	rc = sock_register(&atalk_family_ops);
+	if (rc)
+		goto out_proto;
+
 	ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
 	if (!ddp_dl)
 		printk(atalk_err_snap);
@@ -1923,12 +1927,33 @@ static int __init atalk_init(void)
 	dev_add_pack(&ltalk_packet_type);
 	dev_add_pack(&ppptalk_packet_type);
 
-	register_netdevice_notifier(&ddp_notifier);
+	rc = register_netdevice_notifier(&ddp_notifier);
+	if (rc)
+		goto out_sock;
+
 	aarp_proto_init();
-	atalk_proc_init();
-	atalk_register_sysctl();
+	rc = atalk_proc_init();
+	if (rc)
+		goto out_aarp;
+
+	rc = atalk_register_sysctl();
+	if (rc)
+		goto out_proc;
 out:
 	return rc;
+out_proc:
+	atalk_proc_exit();
+out_aarp:
+	aarp_cleanup_module();
+	unregister_netdevice_notifier(&ddp_notifier);
+out_sock:
+	dev_remove_pack(&ppptalk_packet_type);
+	dev_remove_pack(&ltalk_packet_type);
+	unregister_snap_client(ddp_dl);
+	sock_unregister(PF_APPLETALK);
+out_proto:
+	proto_unregister(&ddp_proto);
+	goto out;
 }
 module_init(atalk_init);
 

net/appletalk/sysctl_net_atalk.c

@@ -45,9 +45,12 @@ static struct ctl_table atalk_table[] = {
 
 static struct ctl_table_header *atalk_table_header;
 
-void atalk_register_sysctl(void)
+int __init atalk_register_sysctl(void)
 {
 	atalk_table_header = register_net_sysctl(&init_net, "net/appletalk", atalk_table);
+	if (!atalk_table_header)
+		return -ENOMEM;
+	return 0;
 }
 
 void atalk_unregister_sysctl(void)