Re: [PATCH] dm crypt: Convert essiv from ahash to shash

[Arnd Bergmann]

On Mon, Jul 16, 2018 at 5:59 AM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> In preparing to remove all stack VLA usage from the kernel[1], this
> removes the discouraged use of AHASH_REQUEST_ON_STACK in favor of
> the smaller SHASH_DESC_ON_STACK by converting from ahash-wrapped-shash
> to direct shash. The stack allocation will be made a fixed size in a
> later patch to the crypto subsystem.
>
> [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

This looks very nice, it should also make the operation more efficient in the
process by removing one indirection layer.

     Arnd