Re: [PATCH v6 0/8] crypto: qce - Fix crypto self-test failures

[Eric Biggers]

On Thu, Jul 23, 2026 at 01:27:04PM -0700, Eric Biggers wrote:
> On Fri, Jul 17, 2026 at 05:53:29PM +0200, Bartosz Golaszewski wrote:
> > This extends the initial submission from Kuldeep.
> > 
> > The QCE hardware crypto engine has several limitations that cause it to
> > produce incorrect results or stall on certain inputs. This series fixes
> > several bugs and adds workaround allowing the deiver to pass crypto
> > self-tests.
> > 
> > The failures addressed are:

I also noticed that qce_aead_done() compares MACs using memcmp() instead
of crypto_memneq().  That makes it vulnerable to timing side-channel
attacks (https://en.wikipedia.org/wiki/Timing_attack).

This is yet another thing that is inconsistent with claims that this
driver improves security.

Of course, the software implementation does not have this problem.

- Eric