From b4ef4ce09308955d1aa54a289c0162607b3aa16c Mon Sep 17 00:00:00 2001 From: Sergey Popovich Date: Fri, 6 Dec 2013 10:57:19 +0200 Subject: [PATCH] netfilter: xt_hashlimit: fix proc entry leak in netns destroy path In (32263dd1b netfilter: xt_hashlimit: fix namespace destroy path) the hashlimit_net_exit() function is always called right before hashlimit_mt_destroy() to release netns data. If you use xt_hashlimit with IPv4 and IPv6 together, this produces the following splat via netconsole in the netns destroy path: Pid: 9499, comm: kworker/u:0 Tainted: G WC O 3.2.0-5-netctl-amd64-core2 Call Trace: [] ? warn_slowpath_common+0x78/0x8c [] ? warn_slowpath_fmt+0x45/0x4a [] ? remove_proc_entry+0xd8/0x22e [] ? kfree+0x5b/0x6c [] ? hashlimit_net_exit+0x45/0x8d [xt_hashlimit] [] ? ops_exit_list+0x1c/0x44 [] ? cleanup_net+0xf1/0x180 [] ? should_resched+0x5/0x23 [] ? process_one_work+0x161/0x269 [] ? cwq_activate_delayed_work+0x3c/0x48 [] ? worker_thread+0xc2/0x145 [] ? manage_workers.isra.25+0x15b/0x15b [] ? kthread+0x76/0x7e [] ? kernel_thread_helper+0x4/0x10 [] ? kthread_worker_fn+0x139/0x139 [] ? gs_change+0x13/0x13 ---[ end trace d8c3cc0ad163ef79 ]--- ------------[ cut here ]------------ WARNING: at /usr/src/linux-3.2.52/debian/build/source_netctl/fs/proc/generic.c:849 remove_proc_entry+0x217/0x22e() Hardware name: remove_proc_entry: removing non-empty directory 'net/ip6t_hashlimit', leaking at least 'IN-REJECT' This is due to lack of removal net/ip6t_hashlimit/* entries in hashlimit_proc_net_exit(), since only IPv4 entries are deleted. Fix it by always removing the IPv4 and IPv6 entries and their parent directories in the netns destroy path. Signed-off-by: Sergey Popovich Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_hashlimit.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 9ff035c71403..a3910fc2122b 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -325,21 +325,24 @@ static void htable_gc(unsigned long htlong) add_timer(&ht->timer); } -static void htable_destroy(struct xt_hashlimit_htable *hinfo) +static void htable_remove_proc_entry(struct xt_hashlimit_htable *hinfo) { struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); struct proc_dir_entry *parent; - del_timer_sync(&hinfo->timer); - if (hinfo->family == NFPROTO_IPV4) parent = hashlimit_net->ipt_hashlimit; else parent = hashlimit_net->ip6t_hashlimit; - if(parent != NULL) + if (parent != NULL) remove_proc_entry(hinfo->name, parent); +} +static void htable_destroy(struct xt_hashlimit_htable *hinfo) +{ + del_timer_sync(&hinfo->timer); + htable_remove_proc_entry(hinfo); htable_selective_cleanup(hinfo, select_all); kfree(hinfo->name); vfree(hinfo); @@ -883,21 +886,15 @@ static int __net_init hashlimit_proc_net_init(struct net *net) static void __net_exit hashlimit_proc_net_exit(struct net *net) { struct xt_hashlimit_htable *hinfo; - struct proc_dir_entry *pde; struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); - /* recent_net_exit() is called before recent_mt_destroy(). Make sure - * that the parent xt_recent proc entry is is empty before trying to - * remove it. + /* hashlimit_net_exit() is called before hashlimit_mt_destroy(). + * Make sure that the parent ipt_hashlimit and ip6t_hashlimit proc + * entries is empty before trying to remove it. */ mutex_lock(&hashlimit_mutex); - pde = hashlimit_net->ipt_hashlimit; - if (pde == NULL) - pde = hashlimit_net->ip6t_hashlimit; - hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) - remove_proc_entry(hinfo->name, pde); - + htable_remove_proc_entry(hinfo); hashlimit_net->ipt_hashlimit = NULL; hashlimit_net->ip6t_hashlimit = NULL; mutex_unlock(&hashlimit_mutex);