[PATCH] crypto: vmx - fix copy-paste error in CTR mode

[Ondrej Mosnáček]

Hi Daniel,

pi 15. 3. 2019 o 3:09 Daniel Axtens <dja at axtens.net> napísal(a):
> The original assembly imported from OpenSSL has two copy-paste
> errors in handling CTR mode. When dealing with a 2 or 3 block tail,
> the code branches to the CBC decryption exit path, rather than to
> the CTR exit path.
>
> This leads to corruption of the IV, which leads to subsequent blocks
> being corrupted.
>
> This can be detected with libkcapi test suite, which is available at
> https://github.com/smuellerDD/libkcapi
>
> Reported-by: Ondrej Mosnáček <omosnacek at gmail.com>
> Fixes: 5c380d623ed3 ("crypto: vmx - Add support for VMS instructions by ASM")
> Cc: stable at vger.kernel.org
> Signed-off-by: Daniel Axtens <dja at axtens.net>

Thank you for looking into this and for posting the patch(es)! I
tested the patch yesterday and I can confirm that it makes the
libkcapi tests/reproducer pass.

Assuming you will want to cover the other failures from the new
testmgr tests by a separate patch:

Tested-by: Ondrej Mosnacek <omosnacek at gmail.com>

> ---
>  drivers/crypto/vmx/aesp8-ppc.pl | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/crypto/vmx/aesp8-ppc.pl b/drivers/crypto/vmx/aesp8-ppc.pl
> index d6a9f63d65ba..de78282b8f44 100644
> --- a/drivers/crypto/vmx/aesp8-ppc.pl
> +++ b/drivers/crypto/vmx/aesp8-ppc.pl
> @@ -1854,7 +1854,7 @@ Lctr32_enc8x_three:
>         stvx_u          $out1,$x10,$out
>         stvx_u          $out2,$x20,$out
>         addi            $out,$out,0x30
> -       b               Lcbc_dec8x_done
> +       b               Lctr32_enc8x_done
>
>  .align 5
>  Lctr32_enc8x_two:
> @@ -1866,7 +1866,7 @@ Lctr32_enc8x_two:
>         stvx_u          $out0,$x00,$out
>         stvx_u          $out1,$x10,$out
>         addi            $out,$out,0x20
> -       b               Lcbc_dec8x_done
> +       b               Lctr32_enc8x_done
>
>  .align 5
>  Lctr32_enc8x_one:
> --
> 2.19.1
>