lkml.org 
[lkml]   [2011]   [Sep]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo
From
> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-09-19 16:33    [W:0.151 / U:11.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site