Re: [PATCH] Make /proc/slabinfo 0400

From: Pekka Enberg
Date: Fri Mar 04 2011 - 17:15:01 EST


On Sat, Mar 5, 2011 at 12:10 AM, Pekka Enberg <penberg@xxxxxxxxxx> wrote:
> I can think of four things that will make things harder for the
> attacker (in the order of least theoretical performance impact):
>
>  (1) disable slub merging
>
>  (2) pin down random objects in the slab during setup (i.e. don't
> allow them to be allocated)
>
>  (3) randomize the initial freelist
>
>  (4) randomize padding between objects in a slab
>
> AFAICT, all of them will make brute force attacks using the kernel
> heap as an attack vector harder but won't prevent them.

There's also a fifth one:

(5) randomize slab page allocation order

which will make it harder to make sure you have full control over a
slab and figure out which allocation lands on it.

Pekka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/