Re: [PATCH] exec: do not leave bprm->interp on stack

From: Kees Cook
Date: Fri Nov 16 2012 - 13:00:35 EST


On Fri, Nov 16, 2012 at 4:50 AM, P J P <ppandit@xxxxxxxxxx> wrote:
>
> Hello folks,
>
> +-- On Mon, 12 Nov 2012, Kees Cook wrote --+
> | > Al, what's your take on the *rare* extra call to request_module?
> |
> | Without any other feedback, I'd like to use my minimal allocation
> | patch, since it fixes the problem and doesn't change any of the
> | semantics of how/when loading happens.
>
> I did apply and test this patch with kernel-3.5.3 on my machine. Now it
> seems to disclose dynamically allocated(kstrdup) bytes, instead of the call
> stack bytes. Recursions still dodge and exceed the limit of
> BINPRM_MAX_RECURSION(4).
>
> Please pardon my asking, but - how is this a fix?

Hrm? It should be showing only the live heap-allocated interp -- are
you seeing uninitialized contents?

-Kees

--
Kees Cook
Chrome OS Security
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