From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57382 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbcLHGUa (ORCPT ); Thu, 8 Dec 2016 01:20:30 -0500 Subject: Patch "net: check dead netns for peernet2id_alloc()" has been added to the 4.4-stable tree To: xiyou.wangcong@gmail.com, avagin@gmail.com, avagin@openvz.org, davem@davemloft.net, gregkh@linuxfoundation.org, nicolas.dichtel@6wind.com Cc: , From: Date: Thu, 08 Dec 2016 07:20:15 +0100 Message-ID: <148117801520121@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled net: check dead netns for peernet2id_alloc() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-check-dead-netns-for-peernet2id_alloc.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Dec 8 07:18:57 CET 2016 From: WANG Cong Date: Wed, 16 Nov 2016 10:27:02 -0800 Subject: net: check dead netns for peernet2id_alloc() From: WANG Cong [ 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 Cc: Nicolas Dichtel Signed-off-by: Cong Wang Acked-by: Andrei Vagin Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/net_namespace.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -217,6 +217,8 @@ int peernet2id_alloc(struct net *net, st 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); Patches currently in stable-queue which might be from xiyou.wangcong@gmail.com are queue-4.4/net-sched-respect-rcu-grace-period-on-cls-destruction.patch queue-4.4/af_unix-conditionally-use-freezable-blocking-calls-in-read.patch queue-4.4/netlink-call-cb-done-from-a-worker-thread.patch queue-4.4/net-check-dead-netns-for-peernet2id_alloc.patch