Re: [PATCH v2 1/3] drm/i915: Reject panel_type > 0xf from VBT

Jani Nikula
2016-04-11T08:08:42Z

On Mon, 11 Apr 2016, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> VBT can only contain 16 panel entries, indexed with the panel_type.
> To play it safe we should reject panel_type > 0xf, so that we don't
> read past the valid data.
>
> v2: Add debug logging (Jani)
>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Rob Kramer <rob@solution-space.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com> (v1)

Yup.

> ---
> drivers/gpu/drm/i915/intel_bios.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index eb756c41d9e1..c8857b5dbfec 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -212,8 +212,11 @@ parse_lfp_panel_data(struct drm_i915_private *dev_priv,
> return;
>
> dev_priv->vbt.lvds_dither = lvds_options->pixel_dither;
> - if (lvds_options->panel_type == 0xff)
> + if (lvds_options->panel_type > 0xf) {
> + DRM_DEBUG_KMS("Invalid VBT panel type 0x%x\n",
> + lvds_options->panel_type);
> return;
> + }
>
> panel_type = lvds_options->panel_type;

--
Jani Nikula, Intel Open Source Technology Center