Re: [PATCH v4 11/14] treewide: Prepare to remove VLA usage for AHASH_REQUEST_ON_STACK

[Kees Cook]

On Thu, Jul 12, 2018 at 5:40 PM, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, Jul 12, 2018 at 06:02:26PM +0200, Arnd Bergmann wrote:
>>
>> Looking through some of the drivers, I found this interesting one:
>
> As I said before these patches are fundamentally broken.  Users
> of AHASH_REQUEST_ON_STACK can only use sync algorithm providers
> and therefore drivers are irrelevant.

I've also now gone to look at the few users of AHASH_REQUEST_ON_STACK,
and it seems like they come in two flavors:

- ones that can be trivially converts to shash (hibernate)
- things that use scatter/gather

Is this correct? It seems like you did the bulk of
AHASH_REQUEST_ON_STACK conversions in 2016. Can shash grow an sg
interface?

-Kees

-- 
Kees Cook
Pixel Security