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From: Kees Cook <kees@ubuntu.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: kernel-hardening@lists.openwall.com,
	Andrew Morton <akpm@linux-foundation.org>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Christoph Lameter <cl@linux-foundation.org>,
	Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo
Date: Wed, 14 Sep 2011 12:27:44 -0700	[thread overview]
Message-ID: <20110914192744.GC4529@outflux.net> (raw)
In-Reply-To: <20110910164134.GA2442@albatros>

Hi Vasiliy,

On Sat, Sep 10, 2011 at 08:41:34PM +0400, Vasiliy Kulikov wrote:
> Historically /proc/slabinfo has 0444 permissions and is accessible to
> the world.  slabinfo contains rather private information related both to
> the kernel and userspace tasks.  Depending on the situation, it might
> reveal either private information per se or information useful to make
> another targeted attack.  Some examples of what can be learned by
> reading/watching for /proc/slabinfo entries:
> ...
> World readable slabinfo simplifies kernel developers' job of debugging
> kernel bugs (e.g. memleaks), but I believe it does more harm than
> benefits.  For most users 0444 slabinfo is an unreasonable attack vector.
> 
> Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>

Haven't had any mass complaints about the 0400 in Ubuntu (sorry Dave!), so
I'm obviously for it.

Reviewed-by: Kees Cook <kees@ubuntu.com>

-Kees

-- 
Kees Cook
Ubuntu Security Team

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  parent reply	other threads:[~2011-09-14 19:29 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20110910164001.GA2342@albatros>
2011-09-10 16:41 ` [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo Vasiliy Kulikov
2011-09-12 15:06   ` Cyrill Gorcunov
2011-09-13  6:28     ` Vasiliy Kulikov
2011-09-14 13:16   ` Vasiliy Kulikov
2011-09-14 15:18     ` Dave Hansen
2011-09-14 15:42       ` [kernel-hardening] " Vasiliy Kulikov
2011-09-14 15:48         ` Vasiliy Kulikov
2011-09-14 18:24         ` Dave Hansen
2011-09-14 18:41   ` Dave Hansen
2011-09-14 19:14     ` Vasiliy Kulikov
2011-09-14 19:27   ` Kees Cook [this message]
2011-09-18 17:05     ` [kernel-hardening] " Vasiliy Kulikov
2011-09-19 13:42       ` Christoph Lameter
2011-09-19 14:30       ` Pekka Enberg
2011-09-19 14:46         ` Vasiliy Kulikov
2011-09-19 15:13           ` Pekka Enberg
2011-09-19 15:57             ` Vasiliy Kulikov
2011-09-19 16:11               ` Pekka Enberg
2011-09-19 16:18                 ` Vasiliy Kulikov
2011-09-19 17:31                   ` Pekka Enberg
2011-09-19 17:35                     ` Vasiliy Kulikov
2011-09-19 17:51                       ` Christoph Lameter
2011-09-19 19:59                         ` Valdis.Kletnieks
2011-09-19 20:02                           ` Christoph Lameter
2011-09-19 20:36                             ` Valdis.Kletnieks
2011-09-19 17:51                       ` Pekka Enberg
2011-09-19 17:58                         ` Vasiliy Kulikov
2011-09-19 18:46                           ` Pekka Enberg
2011-09-19 18:55                             ` Vasiliy Kulikov
2011-09-19 19:20                               ` Pekka Enberg
2011-09-19 19:33                               ` Pekka Enberg
2011-09-19 18:55                             ` Linus Torvalds
2011-09-19 19:18                               ` Pekka Enberg
2011-09-19 19:45                                 ` Pekka Enberg
2011-09-19 20:59                                 ` David Rientjes
2011-09-19 18:03                         ` Dave Hansen
2011-09-19 18:21                           ` Pekka Enberg
2011-09-19 19:45           ` Valdis.Kletnieks
2011-09-19 19:55             ` Alan Cox
2011-09-21 17:05               ` Vasiliy Kulikov
2011-09-22  2:20                 ` Valdis.Kletnieks

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