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 <xiaolou4617@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
linzhang 2017-05-17 12:05:07 +08:00 committed by David S. Miller
parent 3c2ce60bdd
commit 64df6d525f
3 changed files with 22 additions and 11 deletions

View File

@ -298,10 +298,10 @@ void x25_check_rbuf(struct sock *);
/* sysctl_net_x25.c */
#ifdef CONFIG_SYSCTL
void x25_register_sysctl(void);
int x25_register_sysctl(void);
void x25_unregister_sysctl(void);
#else
static inline void x25_register_sysctl(void) {};
static inline int x25_register_sysctl(void) { return 0; };
static inline void x25_unregister_sysctl(void) {};
#endif /* CONFIG_SYSCTL */

View File

@ -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);

View File

@ -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)