Commit 1e47ee83 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso

netfilter: nf_conntrack: fix BUG_ON while removing nf_conntrack with netns

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: default avatarcanqun zhang <canqunzhang@gmail.com>
Acked-by: default avatarGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 4610476d
...@@ -31,6 +31,8 @@ extern void nf_conntrack_cleanup(struct net *net); ...@@ -31,6 +31,8 @@ extern void nf_conntrack_cleanup(struct net *net);
extern int nf_conntrack_proto_init(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_proto_fini(struct net *net);
extern void nf_conntrack_cleanup_end(void);
extern bool extern bool
nf_ct_get_tuple(const struct sk_buff *skb, nf_ct_get_tuple(const struct sk_buff *skb,
unsigned int nhoff, unsigned int nhoff,
......
...@@ -1376,11 +1376,12 @@ void nf_conntrack_cleanup(struct net *net) ...@@ -1376,11 +1376,12 @@ void nf_conntrack_cleanup(struct net *net)
synchronize_net(); synchronize_net();
nf_conntrack_proto_fini(net); nf_conntrack_proto_fini(net);
nf_conntrack_cleanup_net(net); nf_conntrack_cleanup_net(net);
}
if (net_eq(net, &init_net)) { void nf_conntrack_cleanup_end(void)
RCU_INIT_POINTER(nf_ct_destroy, NULL); {
nf_conntrack_cleanup_init_net(); RCU_INIT_POINTER(nf_ct_destroy, NULL);
} nf_conntrack_cleanup_init_net();
} }
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
......
...@@ -575,6 +575,7 @@ static int __init nf_conntrack_standalone_init(void) ...@@ -575,6 +575,7 @@ static int __init nf_conntrack_standalone_init(void)
static void __exit nf_conntrack_standalone_fini(void) static void __exit nf_conntrack_standalone_fini(void)
{ {
unregister_pernet_subsys(&nf_conntrack_net_ops); unregister_pernet_subsys(&nf_conntrack_net_ops);
nf_conntrack_cleanup_end();
} }
module_init(nf_conntrack_standalone_init); module_init(nf_conntrack_standalone_init);
......
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