From: <tan.hu@zte•com.cn>
To: <ja@ssi•bg>
Cc: <wensong@linux-vs•org>, <horms@verge•net.au>,
<pablo@netfilter•org>, <kadlec@blackhole•kfki.hu>, <fw@strlen•de>,
<davem@davemloft•net>, <netdev@vger•kernel.org>,
<lvs-devel@vger•kernel.org>, <netfilter-devel@vger•kernel.org>,
<coreteam@netfilter•org>, <linux-kernel@vger•kernel.org>,
<zhong.weidong@zte•com.cn>, <jiang.biao2@zte•com.cn>
Subject: Re: Re: [PATCH v2] ipvs: fix race between ip_vs_conn_new() andip_vs_del_dest()
Date: Wed, 25 Jul 2018 15:15:49 +0800 (CST) [thread overview]
Message-ID: <201807251515493276583@zte.com.cn> (raw)
In-Reply-To: <alpine.LFD.2.20.1807250849100.2794@ja.home.ssi.bg>
[-- Attachment #1.1: Type: text/plain, Size: 2349 bytes --]
Thanks, patch-v3 has been sent. please check it again.
> Hello,
>
> On Wed, 25 Jul 2018, Tan Hu wrote:
>
> > We came across infinite loop in ipvs when using ipvs in docker
> > env.
> >
> > When ipvs receives new packets and cannot find an ipvs connection,
> > it will create a new connection, then if the dest is unavailable
> > (i.e. IP_VS_DEST_F_AVAILABLE), the packet will be dropped sliently.
> >
> > But if the dropped packet is the first packet of this connection,
> > the connection control timer never has a chance to start and the
> > ipvs connection cannot be released. This will lead to memory leak, or
> > infinite loop in cleanup_net() when net namespace is released like
> > this:
> >
> > ip_vs_conn_net_cleanup at ffffffffa0a9f31a [ip_vs]
> > __ip_vs_cleanup at ffffffffa0a9f60a [ip_vs]
> > ops_exit_list at ffffffff81567a49
> > cleanup_net at ffffffff81568b40
> > process_one_work at ffffffff810a851b
> > worker_thread at ffffffff810a9356
> > kthread at ffffffff810b0b6f
> > ret_from_fork at ffffffff81697a18
> >
> > race condition:
> > CPU1 CPU2
> > ip_vs_in()
> > ip_vs_conn_new()
> > ip_vs_del_dest()
> > __ip_vs_unlink_dest()
> > ~IP_VS_DEST_F_AVAILABLE
> > cp->dest && !IP_VS_DEST_F_AVAILABLE
> > __ip_vs_conn_put
> > ...
> > cleanup_net ---> infinite looping
> >
> > Fix this by checking whether the timer already started.
> >
> > Signed-off-by: Tan Hu <tan.hu@zte•com.cn>
> > Reviewed-by: Jiang Biao <jiang.biao2@zte•com.cn>
> > ---
> > v2: fix use-after-free in CONN_ONE_PACKET case suggested by Julian Anastasov
> >
> > net/netfilter/ipvs/ip_vs_core.c | 15 +++++++++++----
> > 1 file changed, 11 insertions(+), 4 deletions(-)
> >
> > diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
> > index 0679dd1..a17104f 100644
> > --- a/net/netfilter/ipvs/ip_vs_core.c
> > +++ b/net/netfilter/ipvs/ip_vs_core.c
> > @@ -1972,13 +1972,20 @@ static int ip_vs_in_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb,
> > if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
> > /* the destination server is not available */
> >
> > - if (sysctl_expire_nodest_conn(ipvs)) {
> > + __u32 flags = cp->flags;
>
> Ops, now scripts/checkpatch.pl --strict /tmp/file.patch
> is complaining about extra trailing space in above line.
> You can also remove the empty line above the new code...
>
> Regards
prev parent reply other threads:[~2018-07-25 7:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-25 2:49 [PATCH v2] ipvs: fix race between ip_vs_conn_new() and ip_vs_del_dest() Tan Hu
2018-07-25 5:53 ` Julian Anastasov
2018-07-25 7:15 ` tan.hu [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201807251515493276583@zte.com.cn \
--to=tan.hu@zte$(echo .)com.cn \
--cc=coreteam@netfilter$(echo .)org \
--cc=davem@davemloft$(echo .)net \
--cc=fw@strlen$(echo .)de \
--cc=horms@verge$(echo .)net.au \
--cc=ja@ssi$(echo .)bg \
--cc=jiang.biao2@zte$(echo .)com.cn \
--cc=kadlec@blackhole$(echo .)kfki.hu \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=lvs-devel@vger$(echo .)kernel.org \
--cc=netdev@vger$(echo .)kernel.org \
--cc=netfilter-devel@vger$(echo .)kernel.org \
--cc=pablo@netfilter$(echo .)org \
--cc=wensong@linux-vs$(echo .)org \
--cc=zhong.weidong@zte$(echo .)com.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox