Commit 64df6d52 authored by linzhang's avatar linzhang Committed by David S. Miller
Browse files

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: default avatarlinzhang <xiaolou4617@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3c2ce60b

include/net/x25.h

+2 −2
Original line number Diff line number Diff line
@@ -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 */

net/x25/af_x25.c

+16 −8
Original line number Diff line number Diff line
@@ -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;



	pr_info("Linux Version 0.2\n");

	rc = x25_register_sysctl();

	if (rc)

		goto out_dev;



	x25_register_sysctl();

	rc = x25_proc_init();

	if (rc != 0)

		goto out_dev;

	if (rc)

		goto out_sysctl;



	pr_info("Linux Version 0.2\n");



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);

net/x25/sysctl_net_x25.c

+4 −1
Original line number Diff line number Diff line
@@ -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)

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