diff options
| author | WANG Cong <xiyou.wangcong@gmail.com> | 2016-11-16 10:27:02 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-12-10 19:07:22 +0100 |
| commit | 2b54505c877f71155c7aba26550015bd1e30d3dc (patch) | |
| tree | ea46dce8871ea35ae2faf28cb3d1d0f02c67b852 /net | |
| parent | 790fd11f9ed6d2558a516280c3bd1e25b0c64c90 (diff) | |
net: check dead netns for peernet2id_alloc()
[ Upstream commit cfc44a4d147ea605d66ccb917cc24467d15ff867 ]
Andrei reports we still allocate netns ID from idr after we destroy
it in cleanup_net().
cleanup_net():
...
idr_destroy(&net->netns_ids);
...
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_exit_list(ops, &net_exit_list);
-> rollback_registered_many()
-> rtmsg_ifinfo_build_skb()
-> rtnl_fill_ifinfo()
-> peernet2id_alloc()
After that point we should not even access net->netns_ids, we
should check the death of the current netns as early as we can in
peernet2id_alloc().
For net-next we can consider to avoid sending rtmsg totally,
it is a good optimization for netns teardown path.
Fixes: 0c7aecd4bde4 ("netns: add rtnl cmd to add and get peer netns ids")
Reported-by: Andrei Vagin <avagin@gmail.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/net_namespace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 2c2eb1b629b1..2e9a1c2818c7 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -217,6 +217,8 @@ int peernet2id_alloc(struct net *net, struct net *peer) bool alloc; int id; + if (atomic_read(&net->count) == 0) + return NETNSA_NSID_NOT_ASSIGNED; spin_lock_irqsave(&net->nsid_lock, flags); alloc = atomic_read(&peer->count) == 0 ? false : true; id = __peernet2id_alloc(net, peer, &alloc); |