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: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 999a982..becb048 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2957,10 +2957,6 @@
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 @@
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 @@
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 @@
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 @@
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();
