[Intel-gfx] [PATCH] drm/i915/bios: fix off by one in parse_generic_dtd()

[Matt Roper]

On Thu, Dec 12, 2019 at 12:11:30PM +0300, Dan Carpenter wrote:
> The "num_dtd" variable is the number of elements in the
> generic_dtd->dtd[] array so the > needs to be >= to prevent reading one
> element beyond the end of the array.
> 
> Fixes: 33ef6d4fd8df ("drm/i915/vbt: Handle generic DTD block")
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_bios.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index 1aeecdd02293..d1e27ee86e53 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -338,7 +338,7 @@ parse_generic_dtd(struct drm_i915_private *dev_priv,
>  
>  	num_dtd = (get_blocksize(generic_dtd) -
>  		   sizeof(struct bdb_generic_dtd)) / generic_dtd->gdtd_size;
> -	if (dev_priv->vbt.panel_type > num_dtd) {
> +	if (dev_priv->vbt.panel_type >= num_dtd) {
>  		DRM_ERROR("Panel type %d not found in table of %d DTD's\n",
>  			  dev_priv->vbt.panel_type, num_dtd);
>  		return;
> -- 
> 2.11.0
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795