From: Pekka Enberg <penberg@cs.helsinki.fi>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
kernel-hardening@lists.openwall.com, Kees Cook <kees@ubuntu.com>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Christoph Lameter <cl@linux-foundation.org>,
Matt Mackall <mpm@selenic.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Dan Rosenberg <drosenberg@vsecurity.com>,
Theodore Tso <tytso@mit.edu>, Alan Cox <alan@linux.intel.com>,
Jesper Juhl <jj@chaosbits.net>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo
Date: Mon, 19 Sep 2011 17:30:49 +0300 [thread overview]
Message-ID: <CAOJsxLF8DBEC9o9pSwa6c6pMg8ByFBdsDnzg22P3ucQcP98uzA@mail.gmail.com> (raw)
In-Reply-To: <20110918170512.GA2351@albatros>
> On Wed, Sep 14, 2011 at 12:27 -0700, Kees Cook wrote:
>> 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>
On Sun, Sep 18, 2011 at 8:05 PM, Vasiliy Kulikov <segoon@openwall.com> wrote:
>> 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>
>
> Looks like the members of the previous slabinfo discussion don't object
> against the patch now and it got two other Reviewed-by responses. Can
> you merge it as-is or should I probably convince someone else?
We discussed this in March (google for 'Make /proc/slabinfo 0400') and
concluded that it's not worth it doesn't really protect from anything
and causes harm to developers.
Pekka
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next prev parent reply other threads:[~2011-09-19 14:30 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110910164001.GA2342@albatros>
2011-09-10 16:41 ` 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
2011-09-18 17:05 ` [kernel-hardening] " Vasiliy Kulikov
2011-09-19 13:42 ` Christoph Lameter
2011-09-19 14:30 ` Pekka Enberg [this message]
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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