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From: "Serge E. Hallyn" <serge@hallyn.com>
To: Serge Hallyn <serge@hallyn.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	"Daniel P. Berrange" <berrange@redhat.com>,
	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: Mon, 6 Aug 2012 19:20:40 +0000	[thread overview]
Message-ID: <20120806192040.GA27023@mail.hallyn.com> (raw)
In-Reply-To: <1344122135.1422.2.camel@Nokia-N900-51-1>

Quoting Serge Hallyn (serge@hallyn.com):
> Eric,
> 
> during the container reboot discussion, the agreement was reached that rebooting for real fron non-init pid ns is not safe.  Restarting userspace (in pidns caller owns) is.  I argue the same reasoning supports this.
> 
> I haven't had a chance to review the patch, but the idea gets my ack.  I'll look at the patch asap.
> 
> I'm also fine with splitting cap_sys_boot into a user and system caps.  The former would only be needed targeted to the userns of the init pid, while the latter would be required to init_user_ns.  Then containers could safely be given cap_sys_restart or whatever, but not cap_sys_boot which authorizes kexec and machine reset/poweroff.

Splitting the cap up into CAP_RESTART (restart /sbin/init) and CAP_BOOT
(reboot hardware or kexec kernel) has the advantage that the capabilities
each remain simpler to parse, no 'in this context it means that'.

  reply	other threads:[~2012-08-06 19:19 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
2012-08-04 23:15       ` Serge Hallyn
2012-08-06 19:20         ` Serge E. Hallyn [this message]
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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