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From: Ben Hutchings <ben@decadent.org.uk>
To: kernel-hardening@lists.openwall.com,
	"Robert Święcki" <robert@swiecki.net>,
	"Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Richard Weinberger <richard@nod.at>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Dmitry Vyukov <dvyukov@google.com>,
	David Howells <dhowells@redhat.com>,
	Kostya Serebryany <kcc@google.com>,
	Alexander Potapenko <glider@google.com>,
	Eric Dumazet <edumazet@google.com>,
	Sasha Levin <sasha.levin@oracle.com>,
	"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [kernel-hardening] Re: [PATCH 2/2] sysctl: allow CLONE_NEWUSER to be disabled
Date: Sat, 23 Jan 2016 00:59:59 +0000	[thread overview]
Message-ID: <1453510799.3734.153.camel@decadent.org.uk> (raw)
In-Reply-To: <CAGXu5jKbroEt0nO=yA4V6esKePseO75tcsK=YVy-=1NEuzwxzQ@mail.gmail.com>

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On Fri, 2016-01-22 at 15:00 -0800, Kees Cook wrote:
> On Fri, Jan 22, 2016 at 2:55 PM, Robert Święcki <robert@swiecki.net> wrote:
> > 2016-01-22 23:50 GMT+01:00 Kees Cook <keescook@chromium.org>:
> > 
> > > > Seems that Debian and some older Ubuntu versions are already using
> > > > 
> > > > $ sysctl -a | grep usern
> > > > kernel.unprivileged_userns_clone = 0
> > > > 
> > > > Shall we be consistent wit it?
> > > 
> > > Oh! I didn't see that on systems I checked. On which version did you find that?
> > 
> > $ uname -a
> > Linux bc1 4.3.0-0.bpo.1-amd64 #1 SMP Debian 4.3.3-5~bpo8+1
> > (2016-01-07) x86_64 GNU/Linux
> > $ cat /etc/debian_version
> > 8.2
> 
> Ah-ha, Debian only, though it looks like this was just committed to
> the Ubuntu kernel tree too:
> 
> 
> > IIRC some older kernels delivered with Ubuntu Precise were also using
> > it (but maybe I'm mistaken)
> 
> I don't see it there.
> 
> I think my patch is more complete, but I'm happy to change the name if
> this sysctl has already started to enter the global consciousness. ;)
> 
> Serge, Ben, what do you think?

I agree that using the '_restrict' suffix for new restrictions makes
sense.  I also don't think that a third possible value for
kernel.unprivileged_userns_clone would would be understandable.

I would probably make kernel.unprivileged_userns_clone a wrapper for
kernel.userns_restrict in Debian, then deprecate and eventually remove
it.

Ben.

-- 
Ben Hutchings
Life is what happens to you while you're busy making other plans.
                                                               - John Lennon

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  parent reply	other threads:[~2016-01-23  1:00 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-22 22:39 [PATCH 0/2] sysctl: allow CLONE_NEWUSER to be disabled Kees Cook
2016-01-22 22:39 ` [PATCH 1/2] sysctl: expand use of proc_dointvec_minmax_sysadmin Kees Cook
2016-01-23  3:10   ` Eric W. Biederman
2016-01-23 22:25     ` [kernel-hardening] " Jann Horn
2016-01-24  1:20       ` Eric W. Biederman
2016-01-24  1:43         ` Al Viro
2016-01-24  1:56           ` Jann Horn
2016-01-24  6:02             ` Eric W. Biederman
2016-01-24  6:32               ` Jann Horn
2016-01-24  6:44                 ` Eric W. Biederman
2016-01-22 22:39 ` [PATCH 2/2] sysctl: allow CLONE_NEWUSER to be disabled Kees Cook
2016-01-22 22:47   ` Robert Święcki
2016-01-22 22:50     ` Kees Cook
2016-01-22 22:55       ` Robert Święcki
2016-01-22 23:00         ` Kees Cook
2016-01-23  0:44           ` Serge Hallyn
2016-01-23  0:44           ` Serge Hallyn
2016-01-23  0:59           ` Ben Hutchings [this message]
2016-01-24 20:59             ` [kernel-hardening] " Kees Cook
2016-01-24 22:20               ` Andy Lutomirski
2016-01-25 18:51                 ` Kees Cook
2016-01-22 22:49 ` [PATCH 0/2] " Richard Weinberger
2016-01-23  3:02 ` Eric W. Biederman
2016-01-24 20:57   ` Kees Cook
2016-01-26  7:38     ` [kernel-hardening] " Serge Hallyn
2016-01-24 22:22   ` Andy Lutomirski
2016-01-25 18:51     ` Kees Cook
2016-01-25 18:53       ` Andy Lutomirski
2016-01-25 18:56         ` Kees Cook
2016-01-25 19:33           ` Eric W. Biederman
2016-01-25 22:34             ` Kees Cook
2016-01-25 23:33               ` Andy Lutomirski
2016-01-26  2:27               ` [kernel-hardening] " Daniel Micay
2016-01-26  4:57               ` Eric W. Biederman
2016-01-26 14:38                 ` Josh Boyer
2016-01-26 14:46                   ` Austin S. Hemmelgarn
2016-01-26 14:56                     ` Josh Boyer
2016-01-26 17:20                       ` [kernel-hardening] " Serge Hallyn
2016-01-26 19:56                         ` Josh Boyer
2016-01-26 20:11                           ` Austin S. Hemmelgarn
2016-01-26 17:15                   ` Serge Hallyn
2016-01-26 18:09                     ` Austin S. Hemmelgarn
2016-01-26 18:27                       ` Andy Lutomirski
2016-01-26 18:45                         ` Austin S. Hemmelgarn
2016-01-26 23:15                         ` Kees Cook
2016-01-26 23:13                     ` Kees Cook
2016-01-27 10:27                       ` Eric W. Biederman
2016-01-27 12:32                         ` Austin S. Hemmelgarn
2016-01-28 14:41                         ` Robert Święcki
2016-01-26 16:37                 ` Kees Cook
2016-01-28  8:56                 ` [kernel-hardening] " Serge E. Hallyn
2016-01-28 12:53                   ` Austin S. Hemmelgarn

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