Commit d189634e authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

ipv6: Move ipv6 proc file registration to end of init order 



/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.

This opens up a short time frame to access fib_table_hash with its pants
down.

Move the registration of the proc files to a later point in the init
order to avoid the race.

Tested :-)

Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8cfe523a

net/ipv6/route.c

+31 −10
Original line number Diff line number Diff line
@@ -2957,10 +2957,6 @@ static int __net_init ip6_route_net_init(struct net *net) 
	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;

	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;



#ifdef CONFIG_PROC_FS

	proc_net_fops_create(net, "ipv6_route", 0, &ipv6_route_proc_fops);

	proc_net_fops_create(net, "rt6_stats", S_IRUGO, &rt6_stats_seq_fops);

#endif

	net->ipv6.ip6_rt_gc_expire = 30*HZ;



	ret = 0;
@@ -2981,10 +2977,6 @@ out_ip6_dst_ops: 


static void __net_exit ip6_route_net_exit(struct net *net)

{

#ifdef CONFIG_PROC_FS

	proc_net_remove(net, "ipv6_route");

	proc_net_remove(net, "rt6_stats");

#endif

	kfree(net->ipv6.ip6_null_entry);

#ifdef CONFIG_IPV6_MULTIPLE_TABLES

	kfree(net->ipv6.ip6_prohibit_entry);
@@ -2993,11 +2985,33 @@ static void __net_exit ip6_route_net_exit(struct net *net) 
	dst_entries_destroy(&net->ipv6.ip6_dst_ops);

}



static int __net_init ip6_route_net_init_late(struct net *net)

{

#ifdef CONFIG_PROC_FS

	proc_net_fops_create(net, "ipv6_route", 0, &ipv6_route_proc_fops);

	proc_net_fops_create(net, "rt6_stats", S_IRUGO, &rt6_stats_seq_fops);

#endif

	return 0;

}



static void __net_exit ip6_route_net_exit_late(struct net *net)

{

#ifdef CONFIG_PROC_FS

	proc_net_remove(net, "ipv6_route");

	proc_net_remove(net, "rt6_stats");

#endif

}



static struct pernet_operations ip6_route_net_ops = {

	.init = ip6_route_net_init,

	.exit = ip6_route_net_exit,

};



static struct pernet_operations ip6_route_net_late_ops = {

	.init = ip6_route_net_init_late,

	.exit = ip6_route_net_exit_late,

};



static struct notifier_block ip6_route_dev_notifier = {

	.notifier_call = ip6_route_dev_notify,

	.priority = 0,
@@ -3047,19 +3061,25 @@ int __init ip6_route_init(void) 
	if (ret)

		goto xfrm6_init;



	ret = register_pernet_subsys(&ip6_route_net_late_ops);

	if (ret)

		goto fib6_rules_init;



	ret = -ENOBUFS;

	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) ||

	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||

	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL))

		goto fib6_rules_init;

		goto out_register_late_subsys;



	ret = register_netdevice_notifier(&ip6_route_dev_notifier);

	if (ret)

		goto fib6_rules_init;

		goto out_register_late_subsys;



out:

	return ret;



out_register_late_subsys:

	unregister_pernet_subsys(&ip6_route_net_late_ops);

fib6_rules_init:

	fib6_rules_cleanup();

xfrm6_init:
@@ -3078,6 +3098,7 @@ out_kmem_cache: 
void ip6_route_cleanup(void)

{

	unregister_netdevice_notifier(&ip6_route_dev_notifier);

	unregister_pernet_subsys(&ip6_route_net_late_ops);

	fib6_rules_cleanup();

	xfrm6_fini();

	fib6_gc_cleanup();

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