From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>
Subject: Re: [RFC] capabilities: Ambient capabilities
Date: Fri, 24 Apr 2015 13:18:44 -0700
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To: Christoph Lameter <cl-vYTEC60ixJUAvxtiuMwx3w@public.gmane.org>
Cc: Serge Hallyn <serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>, Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>, Andrew Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Ted Ts'o <tytso-3s7WtUTddSA@public.gmane.org>, Andrew Morton <akpm-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>, "Andrew G. Morgan" <morgan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Mimi Zohar <zohar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>, Michael Kerrisk <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Austin S Hemmelgarn <ahferroin7-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, linux-security-module <linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Aaron Jones <aaronmdjones-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Markku Savela <msa-kXoF896ld44xHbG02/KK1g@public.gmane.org>, Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>
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On Fri, Apr 24, 2015 at 1:13 PM, Christoph Lameter <cl-vYTEC60ixJUAvxtiuMwx3w@public.gmane.org> wrote:
> On Fri, 24 Apr 2015, Andy Lutomirski wrote:
>
>> That's sort of what my patch does -- you need CAP_SETPCAP to switch
>> the securebit.
>>
>> But Christoph's patch required it to add caps to the ambient set, right?
>
> Yes but you seem to be just adding one additional step without too much of
> a benefit because you still need CAP_SETPCAP.
>

No, because I set the default to on :)

Also, in my model you can do:

$ sudo capset cap_whatever=eip something
$ ./something

and the program can make its cap be ambient and run a helper.  In the
CAP_SETPCAP model, that doesn't work.

--Andy

-- 
Andy Lutomirski
AMA Capital Management, LLC