From: Andy Lutomirski <luto@amacapital.net>
To: Kees Cook <keescook@chromium.org>
Cc: "kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
"Robert Święcki" <robert@swiecki.net>,
"Serge E. Hallyn" <serge.hallyn@ubuntu.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Richard Weinberger" <richard@nod.at>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"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: Sun, 24 Jan 2016 14:20:42 -0800 [thread overview]
Message-ID: <CALCETrWUH0qYTJyiu-FEeV59bTDn4zwyak4ZCrzuv4aLWrr-bg@mail.gmail.com> (raw)
In-Reply-To: <CAGXu5j+3==XC2jtHt1_N1hMVbRaUE4cVBQ_DWZo+82rQoXcgMA@mail.gmail.com>
On Sun, Jan 24, 2016 at 12:59 PM, Kees Cook <keescook@chromium.org> wrote:
> On Fri, Jan 22, 2016 at 4:59 PM, Ben Hutchings <ben@decadent.org.uk> wrote:
>> 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.
>
> Okay, cool. We'll keep my patch as-is then. Thanks!
We still need to deal with the capable check in the write handler though, right?
But I must be missing something: why is mode 0644 insufficient?
--Andy
next prev parent reply other threads:[~2016-01-24 22:21 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 ` [kernel-hardening] " Ben Hutchings
2016-01-24 20:59 ` Kees Cook
2016-01-24 22:20 ` Andy Lutomirski [this message]
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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