[stable-3.7,12/14] netfilter: nf_conntrack: fix BUG_ON while removing nf_conntrack with netns

Message ID 1359401493-6196-13-git-send-email-pablo@netfilter.org
State Awaiting Upstream
Delegated to: Pablo Neira
Headers show

Commit Message

Pablo Neira Ayuso Jan. 28, 2013, 7:31 p.m.
From: Pablo Neira Ayuso <pablo@netfilter.org>

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 <canqunzhang@gmail.com>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
 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)
-	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)
+	nf_conntrack_cleanup_end();