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Date: Fri, 25 Feb 2011 22:02:05 +0300
From: Vasiliy Kulikov <segoon@openwall.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kuznet@ms2.inr.ac.ru,
        pekkas@netcore.fi, jmorris@namei.org, yoshfuji@linux-ipv6.org,
        kaber@trash.net, eric.dumazet@gmail.com, therbert@google.com,
        xiaosuo@gmail.com, jesse@nicira.com,
        Kees Cook <kees.cook@canonical.com>, Eugene Teo <eugene@redhat.com>,
        Dan Rosenberg <dan.j.rosenberg@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] don't allow CAP_NET_ADMIN to load non-netdev kernel
 modules
Message-ID: <20110225190205.GA4541@albatros>
References: <1298565265.2613.16.camel@bwh-desktop>
 <20110225123023.GA8776@albatros>
 <20110225151414.GA5211@albatros>
 <20110225.104720.71110261.davem@davemloft.net>
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On Fri, Feb 25, 2011 at 10:47 -0800, David Miller wrote:
> From: Vasiliy Kulikov <segoon@openwall.com>
> Date: Fri, 25 Feb 2011 18:14:14 +0300
> 
> > Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with
> > CAP_NET_ADMIN may load any module from /lib/modules/.  This doesn't mean
> > that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are limited
> > to /lib/modules/**.  However, CAP_NET_ADMIN capability shouldn't allow
> > anybody load any module not related to networking.
> 
> Why go through this naming change, which does break things, instead of
> simply adding a capability mask tag or similar to modules somehow.  You
> could stick it into a special elf section or similar.
>
> Doesn't that make tons more sense than this?

This is not "simply", adding special section for a single workaround
seems like an overkill for me - this touches the core (modules'
internals), which is not related to the initial CAP_* problem at all.

I'd be happy with not breaking anything, but I don't see any acceptable
solution.


Thanks,

-- 
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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