lkml.org 
[lkml]   [2012]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [patch 1/2] c/r: prctl: Add ability to set new mm_struct::exe_file
    On Tue, Mar 20, 2012 at 12:02:44AM +0100, richard -rw- weinberger wrote:
    > On Mon, Mar 19, 2012 at 11:46 PM, Andrew Morton
    > <akpm@linux-foundation.org> wrote:
    > > Well, let's discuss this more completely.  In what ways could an
    > > attacker use this?  How serious is the problem?  What actions can be
    > > taken to lessen it?  etcetera.
    >
    > After considering the problem a bit more I think it's not a big problem.
    > We must not trust /proc/pid/exe in anyway.

    Well, Richard, we probably do not trust it anyway but sysadmins might do
    (and this was another reason for one-shot behaviour -- to not bring
    heart attacks to sysadmins, and everyone would know this link might
    be changed only one time ;)

    > An attacker can always execute another binary without calling execve().

    That's what c/r basically does :)

    >
    > So, why makes that one-short fashion the feature more secure?
    > Let the user change the exe symlink as often as he wants.
    > From a security point of view the exe symlink is anyway useless.

    Maybe better to call it 'predictable' then rather than 'secure'?

    Cyrill
    --
    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: 2012-03-20 00:19    [W:0.023 / U:0.424 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site