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authorWANG Cong <xiyou.wangcong@gmail.com>2016-11-16 10:27:02 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-12-10 19:07:22 +0100
commit2b54505c877f71155c7aba26550015bd1e30d3dc (patch)
treeea46dce8871ea35ae2faf28cb3d1d0f02c67b852 /net
parent790fd11f9ed6d2558a516280c3bd1e25b0c64c90 (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.c2
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);