Eric Lee / smarc-fsl-linux-kernel

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Commit 1e47ee8367babe6a5e8adf44a714c7086657b87e

Authored by Pablo Neira Ayuso
1 parent 4610476d89

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: canqun zhang <canqunzhang@gmail.com>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Showing 3 changed files with 8 additions and 4 deletions Side-by-side Diff

include/net/netfilter/nf_conntrack_core.h
Diff comments   View file @ 1e47ee8
... ... @@ -31,6 +31,8 @@
31 31 extern int nf_conntrack_proto_init(struct net *net);
32 32 extern void nf_conntrack_proto_fini(struct net *net);
33 33  
  34 +extern void nf_conntrack_cleanup_end(void);
  35 +
34 36 extern bool
35 37 nf_ct_get_tuple(const struct sk_buff *skb,
36 38 unsigned int nhoff,
net/netfilter/nf_conntrack_core.c
Diff comments   View file @ 1e47ee8
... ... @@ -1376,11 +1376,12 @@
1376 1376 synchronize_net();
1377 1377 nf_conntrack_proto_fini(net);
1378 1378 nf_conntrack_cleanup_net(net);
  1379 +}
1379 1380  
1380   - if (net_eq(net, &init_net)) {
1381   - RCU_INIT_POINTER(nf_ct_destroy, NULL);
1382   - nf_conntrack_cleanup_init_net();
1383   - }
  1381 +void nf_conntrack_cleanup_end(void)
  1382 +{
  1383 + RCU_INIT_POINTER(nf_ct_destroy, NULL);
  1384 + nf_conntrack_cleanup_init_net();
1384 1385 }
1385 1386  
1386 1387 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
net/netfilter/nf_conntrack_standalone.c
Diff comments   View file @ 1e47ee8
... ... @@ -575,6 +575,7 @@
575 575 static void __exit nf_conntrack_standalone_fini(void)
576 576 {
577 577 unregister_pernet_subsys(&nf_conntrack_net_ops);
  578 + nf_conntrack_cleanup_end();
578 579 }
579 580  
580 581 module_init(nf_conntrack_standalone_init);