From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754625Ab2GIOo1 (ORCPT ); Mon, 9 Jul 2012 10:44:27 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38232 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754435Ab2GIOiP (ORCPT ); Mon, 9 Jul 2012 10:38:15 -0400 Message-Id: <20120709143122.271968053@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 09 Jul 2012 15:31:55 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Thomas Graf , "David S. Miller" Subject: [ 39/48] ipv6: Move ipv6 proc file registration to end of init order In-Reply-To: <20120709143116.348975190@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Graf [ Upstream commit d189634ecab947c10f6f832258b103d0bbfe73cc ] /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 Signed-off-by: Ben Hutchings --- 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 059b9d9..2e21751 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2881,10 +2881,6 @@ 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; @@ -2905,10 +2901,6 @@ 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); @@ -2917,11 +2909,33 @@ 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, @@ -2971,19 +2985,25 @@ 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: @@ -3002,6 +3022,7 @@ 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();