linux-kernel - Re: [PATCH 0/2] sysctl: allow CLONE

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Message-ID: <56A2B209.7000403@nod.at>
Date:	Fri, 22 Jan 2016 23:49:45 +0100
From:	Richard Weinberger <richard@....at>
To:	Kees Cook <keescook@...omium.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Al Viro <viro@...iv.linux.org.uk>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Andy Lutomirski <luto@...capital.net>,
	Robert Święcki <robert@...ecki.net>,
	Dmitry Vyukov <dvyukov@...gle.com>,
	David Howells <dhowells@...hat.com>,
	Miklos Szeredi <mszeredi@...e.cz>,
	Kostya Serebryany <kcc@...gle.com>,
	Alexander Potapenko <glider@...gle.com>,
	Eric Dumazet <edumazet@...gle.com>,
	Sasha Levin <sasha.levin@...cle.com>,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	kernel-hardening@...ts.openwall.com
Subject: Re: [PATCH 0/2] sysctl: allow CLONE_NEWUSER to be disabled

Am 22.01.2016 um 23:39 schrieb Kees Cook:
> There continues to be unexpected side-effects and security exposures
> via CLONE_NEWUSER. For many end-users running distro kernels with
> CONFIG_USER_NS enabled, there is no way to disable this feature when
> desired. As such, this creates a sysctl to restrict CLONE_NEWUSER so
> admins not running containers or Chrome can avoid the risks of this
> feature.

Last time such a patch came up I was not thrilled because hiding
a scary feature behind a knob IMHO doesn't make it any better nor helps
finding issues.
But as userns is still a source of a lot of issues and distros enable
it by default a knob for the admin seems to be a good idea by now. ;-\

Thanks,
//richard