From d189634ecab947c10f6f832258b103d0bbfe73cc Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Mon, 18 Jun 2012 12:08:33 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv6/route.c | 41 +++++++++++++++++++++++++++++++---------- 1 file changed, 31 insertions(+), 10 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 999a982ad3f..becb048d18d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -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(); -- 2.43.2