linux-kernel - Re: [PATCH] ipv4: Namespaceify tcp_max

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 8 Sep 2017 21:35:02 -0700
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     严海双 <yanhaishuang@...s.chinamobile.com>
Cc:     "David S. Miller" <davem@...emloft.net>,
        Alexey Kuznetsov <kuznet@....inr.ac.ru>,
        Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ipv4: Namespaceify tcp_max_orphans knob

On Fri, Sep 8, 2017 at 6:25 PM, 严海双 <yanhaishuang@...s.chinamobile.com> wrote:
>
>
>> On 2017年9月9日, at 上午6:13, Cong Wang <xiyou.wangcong@...il.com> wrote:
>>
>> On Wed, Sep 6, 2017 at 8:10 PM, Haishuang Yan
>> <yanhaishuang@...s.chinamobile.com> wrote:
>>> Different namespace application might require different maximal number
>>> of TCP sockets independently of the host.
>>
>> So after your patch we could have N * net->ipv4.sysctl_tcp_max_orphans
>> in a whole system, right? This just makes OOM easier to trigger.
>>
>
> From my understanding, before the patch, we had N * net->ipv4.sysctl_tcp_max_orphans,
> and after the patch, we could have ns1.sysctl_tcp_max_orphans + ns2.sysctl_tcp_max_orphans
> + ns3.sysctl_tcp_max_orphans, is that right? Thanks for your reviewing.

Nope, by N I mean the number of containers. Before your patch, the limit
is global, after your patch it is per container.