[Spice-devel] [PATCH spice-server] red-parse-qxl: Reset mask attributes if brush image is missing

[Frediano Ziglio]

ping

> 
> The attributes in this case are not used to apply the mask.
> Doing so avoid sending garbage from the guest which usually
> don't initialise the memory in case the mask is missing.
> Guest should have cleared these bytes by its own however doing so
> on the server fixes the problem too. Considering that these
> command should not appears in newer OSes it's surely not a hot path
> code.
> These garbage came from video memory of the guest so they don't
> contain sensitive data.
> 
> This fixes https://gitlab.freedesktop.org/spice/spice-server/issues/25.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  server/red-parse-qxl.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/server/red-parse-qxl.c b/server/red-parse-qxl.c
> index afae94316..a4ac6a473 100644
> --- a/server/red-parse-qxl.c
> +++ b/server/red-parse-qxl.c
> @@ -626,9 +626,15 @@ static void red_put_brush(SpiceBrush *red)
>  static void red_get_qmask_ptr(RedMemSlotInfo *slots, int group_id,
>                                SpiceQMask *red, QXLQMask *qxl, uint32_t
>                                flags)
>  {
> -    red->flags  = qxl->flags;
> -    red_get_point_ptr(&red->pos, &qxl->pos);
>      red->bitmap = red_get_image(slots, group_id, qxl->bitmap, flags, true);
> +    if (red->bitmap) {
> +        red->flags  = qxl->flags;
> +        red_get_point_ptr(&red->pos, &qxl->pos);
> +    } else {
> +        red->flags  = 0;
> +        red->pos.x = 0;
> +        red->pos.y = 0;
> +    }
>  }
>  
>  static void red_put_qmask(SpiceQMask *red)