From: "Eric W. Biederman" <ebiederm@xmission.com>
To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: linux-kernel@vger.kernel.org,
containers@lists.linux-foundation.org,
Serge Hallyn <serge.hallyn@canonical.com>,
Daniel Lezcano <daniel.lezcano@free.fr>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Tejun Heo <tj@kernel.org>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH] Forbid invocation of kexec_load() outside initial PID namespace
Date: Fri, 03 Aug 2012 06:07:36 -0700 [thread overview]
Message-ID: <bef31b2b-429b-4b2b-981b-b230f9c6bfad@email.android.com> (raw)
In-Reply-To: <20120803125210.GD12870@redhat.com>
"Daniel P. Berrange" <berrange@redhat.com> wrote:
>On Fri, Aug 03, 2012 at 05:45:40AM -0700, Eric W. Biederman wrote:
>> The solution is to use user namespaces and to only test ns_capable on
>the magic reboot path.
>>
>> For the 3.7 timeframe that should be a realistic solution.
>
>Hmm, that would imply that if LXC wants to allow reboot()/CAP_SYS_BOOT
>they will be forced to use CLONE_NEWUSER. I was rather looking for a
>way
>to allow the container to keep CAP_SYS_BOOT, without also mandating use
>of user namespaces.
If we remove the use of CAP_SYS_BOOT on the container reboot path perhaps.
But you have hit one small issue in the huge pile of issues why giving contaners capabilities is generally a bad idea.
This is the reason I have been insisting on a reasonable version of user namespaces for a long time.
When the security issues become important it is time for user namespaces. That is their purpose.
Eric
next prev parent reply other threads:[~2012-08-03 13:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-03 10:53 Daniel P. Berrange
2012-08-03 11:25 ` richard -rw- weinberger
2012-08-03 12:45 ` Eric W. Biederman
2012-08-03 12:52 ` Daniel P. Berrange
2012-08-03 13:07 ` Eric W. Biederman [this message]
2012-08-04 23:15 ` Serge Hallyn
2012-08-06 19:20 ` Serge E. Hallyn
2012-08-06 19:00 ` Serge E. Hallyn
2012-08-06 19:16 ` Eric W. Biederman
2012-08-06 19:24 ` Serge E. Hallyn
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