Re: drm/komeda: Off by one in komeda_fb_get_pixel_addr()

james qian wang (Arm Technology China)
2019-01-24T02:03:30Z

On Wed, Jan 23, 2019 at 12:37:55PM +0300, Dan Carpenter wrote:
> The > should be >= to avoid an off by one bug.
>
> Fixes: c46c24bb6b11 ("drm/komeda: Add komeda_framebuffer")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>
> I'm 98% sure this is correct, but please review it carefully because I'm
> not 100% positive.

Hi Dan:

Thank you, this is a typo and your fix is correct.

Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>

Best Regards
James.

>
> drivers/gpu/drm/arm/display/komeda/komeda_framebuffer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_framebuffer.c b/drivers/gpu/drm/arm/display/komeda/komeda_framebuffer.c
> index 4ddd5314ca23..23ee74d42239 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_framebuffer.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_framebuffer.c
> @@ -144,7 +144,7 @@ komeda_fb_get_pixel_addr(struct komeda_fb *kfb, int x, int y, int plane)
> const struct drm_gem_cma_object *obj;
> u32 plane_x, plane_y, cpp, pitch, offset;
>
> - if (plane > fb->format->num_planes) {
> + if (plane >= fb->format->num_planes) {
> DRM_DEBUG_KMS("Out of max plane num.\n");
> return -EINVAL;
> }