linux-kernel - Re:Re: [PATCH resend] kernel: Make taskstats available via genetlink per namespace

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] [day] [month] [year] [list]

Message-Id: <20220227111618.2043152-1-xu.xin16@zte.com.cn>
Date:   Sun, 27 Feb 2022 11:16:18 +0000
From:   cgel.zte@...il.com
To:     cgel.zte@...il.com, ebiederm@...ssion.com
Cc:     akpm@...ux-foundation.org, balbir@...ux.vnet.ibm.com,
        bsingharora@...il.com, containers@...ts.linux.dev,
        deng.changcheng@....com.cn, linux-kernel@...r.kernel.org,
        xu.xin16@....com.cn
Subject: Re:Re: [PATCH resend] kernel: Make taskstats available via genetlink per namespace

>>> -sh-4.4# ./getdelays -d -p 186 -v
>>> print delayacct stats ON
>>> debug on
>>> Error getting family id, errno 0
>>>
>>> As more and more applications are deployed in containers like Docker,
>>> it is necessary to support getdelays to be used in net namespace.
>>> Taskstats is safe for use per namespace as genetlink checks the
>>> capability of namespace message by netlink_ns_capable().
>>>
>>> Make taskstats available via genetlink per namespace.
>>
>> Let me add a polite nack to this patch.
>
>> Taskstats is completely senseless in a network namespace.  There is no
>> translation of identifiers into the context of the receiver of the
>> message.
>
>The interface of taskstats is genetlink that is sensible in net namsespace.
>
>> To make this work requires updating the taskstats code to do something
>> sensible when in a pid namespace, as well as when in a network
>> namespace.
>
> Yes. Taskstats already does convert the input process ID into the task in the
> correspoding pid namsespace. Do you mean to add some check of current user's
> capability like SYS_ADMIN or else?

Actually, here, I think it's meaningful to set the genl_family's netnsok of Taskstat
as true. As you said, Taskstats itself is senseless in a network namespace. So, we
don't have to limit it to the only init_net_ns, it is basically okay to make it
available in all network namespace. Certainly, maybe taskstats itself also needs to
updated, because it does seem to be missing something to just use CAP_NET_ADMIN as the
acquisition restriction of taskstat.

Thanks,
xu xin