From patchwork Mon Jan 28 19:31:31 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [stable-3.7, 12/14] netfilter: nf_conntrack: fix BUG_ON while removing nf_conntrack with netns From: Pablo Neira X-Patchwork-Id: 216345 Message-Id: <1359401493-6196-13-git-send-email-pablo@netfilter.org> To: stable@vger.kernel.org Cc: davem@davemloft.net, netfilter-devel@vger.kernel.org Date: Mon, 28 Jan 2013 20:31:31 +0100 From: Pablo Neira Ayuso canqun zhang reported that we're hitting BUG_ON in the nf_conntrack_destroy path when calling kfree_skb while rmmod'ing the nf_conntrack module. Currently, the nf_ct_destroy hook is being set to NULL in the destroy path of conntrack.init_net. However, this is a problem since init_net may be destroyed before any other existing netns (we cannot assume any specific ordering while releasing existing netns according to what I read in recent emails). Thanks to Gao feng for initial patch to address this issue. Reported-by: canqun zhang Acked-by: Gao feng Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_core.h | 2 ++ net/netfilter/nf_conntrack_core.c | 9 +++++---- net/netfilter/nf_conntrack_standalone.c | 1 + 3 files changed, 8 insertions(+), 4 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index d8f5b9f..e98aeb3 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -31,6 +31,8 @@ extern void nf_conntrack_cleanup(struct net *net); extern int nf_conntrack_proto_init(struct net *net); extern void nf_conntrack_proto_fini(struct net *net); +extern void nf_conntrack_cleanup_end(void); + extern bool nf_ct_get_tuple(const struct sk_buff *skb, unsigned int nhoff, diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 0f241be..ec02168 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1383,11 +1383,12 @@ void nf_conntrack_cleanup(struct net *net) synchronize_net(); nf_conntrack_proto_fini(net); nf_conntrack_cleanup_net(net); +} - if (net_eq(net, &init_net)) { - RCU_INIT_POINTER(nf_ct_destroy, NULL); - nf_conntrack_cleanup_init_net(); - } +void nf_conntrack_cleanup_end(void) +{ + RCU_INIT_POINTER(nf_ct_destroy, NULL); + nf_conntrack_cleanup_init_net(); } void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 9b39432..df8aa3a 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -571,6 +571,7 @@ static int __init nf_conntrack_standalone_init(void) static void __exit nf_conntrack_standalone_fini(void) { unregister_pernet_subsys(&nf_conntrack_net_ops); + nf_conntrack_cleanup_end(); } module_init(nf_conntrack_standalone_init);