Commit 63b7c2eb authored by Ziyang Xuan's avatar Ziyang Xuan Committed by David S. Miller
Browse files

net/af_packet: registration process optimization in packet_init() 



Now, register_pernet_subsys() and register_netdevice_notifier() are both
after sock_register(). It can create PF_PACKET socket and process socket
once sock_register() successfully. It is possible PF_PACKET socket is
creating but register_pernet_subsys() and register_netdevice_notifier()
are not registered yet. Thus net->packet.sklist_lock and net->packet.sklist
will be accessed without initialization that is done in packet_net_init().
Although this is a low probability scenario.

Move register_pernet_subsys() and register_netdevice_notifier() to the
front in packet_init(). Correspondingly, adjust the unregister process
in packet_exit().

Signed-off-by: default avatarZiyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2a566f01

net/packet/af_packet.c

+13 −13
Original line number Diff line number Diff line
@@ -4725,37 +4725,37 @@ static struct pernet_operations packet_net_ops = { 


static void __exit packet_exit(void)

{

	unregister_netdevice_notifier(&packet_netdev_notifier);

	unregister_pernet_subsys(&packet_net_ops);

	sock_unregister(PF_PACKET);

	proto_unregister(&packet_proto);

	unregister_netdevice_notifier(&packet_netdev_notifier);

	unregister_pernet_subsys(&packet_net_ops);

}



static int __init packet_init(void)

{

	int rc;



	rc = proto_register(&packet_proto, 0);

	if (rc)

		goto out;

	rc = sock_register(&packet_family_ops);

	if (rc)

		goto out_proto;

	rc = register_pernet_subsys(&packet_net_ops);

	if (rc)

		goto out_sock;

		goto out;

	rc = register_netdevice_notifier(&packet_netdev_notifier);

	if (rc)

		goto out_pernet;

	rc = proto_register(&packet_proto, 0);

	if (rc)

		goto out_notifier;

	rc = sock_register(&packet_family_ops);

	if (rc)

		goto out_proto;



	return 0;



out_pernet:

	unregister_pernet_subsys(&packet_net_ops);

out_sock:

	sock_unregister(PF_PACKET);

out_proto:

	proto_unregister(&packet_proto);

out_notifier:

	unregister_netdevice_notifier(&packet_netdev_notifier);

out_pernet:

	unregister_pernet_subsys(&packet_net_ops);

out:

	return rc;

}