net: x25: fix one potential use-after-free issue
The function x25_init is not properly unregister related resources
on error handler.It is will result in kernel oops if x25_init init
failed, so add properly unregister call on error handler.
Also, i adjust the coding style and make x25_register_sysctl properly
return failure.
Signed-off-by: linzhang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index 8b911c2..5a1a98d 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -1791,32 +1791,40 @@ void x25_kill_by_neigh(struct x25_neigh *nb)
static int __init x25_init(void)
{
- int rc = proto_register(&x25_proto, 0);
+ int rc;
- if (rc != 0)
+ rc = proto_register(&x25_proto, 0);
+ if (rc)
goto out;
rc = sock_register(&x25_family_ops);
- if (rc != 0)
+ if (rc)
goto out_proto;
dev_add_pack(&x25_packet_type);
rc = register_netdevice_notifier(&x25_dev_notifier);
- if (rc != 0)
+ if (rc)
goto out_sock;
+ rc = x25_register_sysctl();
+ if (rc)
+ goto out_dev;
+
+ rc = x25_proc_init();
+ if (rc)
+ goto out_sysctl;
+
pr_info("Linux Version 0.2\n");
- x25_register_sysctl();
- rc = x25_proc_init();
- if (rc != 0)
- goto out_dev;
out:
return rc;
+out_sysctl:
+ x25_unregister_sysctl();
out_dev:
unregister_netdevice_notifier(&x25_dev_notifier);
out_sock:
+ dev_remove_pack(&x25_packet_type);
sock_unregister(AF_X25);
out_proto:
proto_unregister(&x25_proto);
diff --git a/net/x25/sysctl_net_x25.c b/net/x25/sysctl_net_x25.c
index a06dfe1..ba078c8 100644
--- a/net/x25/sysctl_net_x25.c
+++ b/net/x25/sysctl_net_x25.c
@@ -73,9 +73,12 @@ static struct ctl_table x25_table[] = {
{ },
};
-void __init x25_register_sysctl(void)
+int __init x25_register_sysctl(void)
{
x25_table_header = register_net_sysctl(&init_net, "net/x25", x25_table);
+ if (!x25_table_header)
+ return -ENOMEM;
+ return 0;
}
void x25_unregister_sysctl(void)
