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

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/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: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Graf 2012-06-18 12:08:33 +00:00 committed by David S. Miller
parent 8cfe523a12
commit d189634eca
1 changed files with 31 additions and 10 deletions
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41
net/ipv6/route.c
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@ -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_mtu_expires = 10*60*HZ;
net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 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; net->ipv6.ip6_rt_gc_expire = 30*HZ;
ret = 0; ret = 0;
@ -2981,10 +2977,6 @@ out_ip6_dst_ops:
static void __net_exit ip6_route_net_exit(struct net *net) 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); kfree(net->ipv6.ip6_null_entry);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES #ifdef CONFIG_IPV6_MULTIPLE_TABLES
kfree(net->ipv6.ip6_prohibit_entry); 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); 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 = { static struct pernet_operations ip6_route_net_ops = {
.init = ip6_route_net_init, .init = ip6_route_net_init,
.exit = ip6_route_net_exit, .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 = { static struct notifier_block ip6_route_dev_notifier = {
.notifier_call = ip6_route_dev_notify, .notifier_call = ip6_route_dev_notify,
.priority = 0, .priority = 0,
@ -3047,19 +3061,25 @@ int __init ip6_route_init(void)
if (ret) if (ret)
goto xfrm6_init; goto xfrm6_init;
ret = register_pernet_subsys(&ip6_route_net_late_ops);
if (ret)
goto fib6_rules_init;
ret = -ENOBUFS; ret = -ENOBUFS;
if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) || 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_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||
__rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, 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); ret = register_netdevice_notifier(&ip6_route_dev_notifier);
if (ret) if (ret)
goto fib6_rules_init; goto out_register_late_subsys;
out: out:
return ret; return ret;
out_register_late_subsys:
unregister_pernet_subsys(&ip6_route_net_late_ops);
fib6_rules_init: fib6_rules_init:
fib6_rules_cleanup(); fib6_rules_cleanup();
xfrm6_init: xfrm6_init:
@ -3078,6 +3098,7 @@ out_kmem_cache:
void ip6_route_cleanup(void) void ip6_route_cleanup(void)
{ {
unregister_netdevice_notifier(&ip6_route_dev_notifier); unregister_netdevice_notifier(&ip6_route_dev_notifier);
unregister_pernet_subsys(&ip6_route_net_late_ops);
fib6_rules_cleanup(); fib6_rules_cleanup();
xfrm6_fini(); xfrm6_fini();
fib6_gc_cleanup(); fib6_gc_cleanup();