Re: [patch 1/2] c/r: prctl: Add ability to set new mm_struct::exe_file

From: richard -rw- weinberger
Date: Mon Mar 19 2012 - 19:02:46 EST


On Mon, Mar 19, 2012 at 11:46 PM, Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> 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.
An attacker can always execute another binary without calling execve().

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.

--
Thanks,
//richard
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