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authorWANG Cong <xiyou.wangcong@gmail.com>2016-11-16 21:27:02 +0300
committerDavid S. Miller <davem@davemloft.net>2016-11-17 19:19:40 +0300
commitcfc44a4d147ea605d66ccb917cc24467d15ff867 (patch)
tree2a4391a568f5771140397b40c422b02568726810 /net
parente5f6f564fd191d365fcd775c06a732a488205588 (diff)
downloadlinux-cfc44a4d147ea605d66ccb917cc24467d15ff867.tar.xz
net: check dead netns for peernet2id_alloc()
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>
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 f61c0e02a413..7001da910c6b 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -219,6 +219,8 @@ 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);