Hello Marek,
I have a similar patch in my tree, so this one is
Reviewed-by: Tobias Jakobi <tjakobi@xxxxxxxxxxxxxxxxxxxxx>
- Tobias
Marek Szyprowski wrote:
> Add a check if the framebuffer described by the provided drm_mode_fb_cmd2
> structure fits into provided GEM buffers. Without this check it is
> possible to create a framebuffer object from a small buffer and set it to
> the hardware, what results in displaying system memory outside the
> allocated GEM buffer.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx # v4.7+
> ---
> This issue was there from the beggining, but the provided patch applies only
> to v4.7+ kernels due to other changes in the fixed code.
> ---
> drivers/gpu/drm/exynos/exynos_drm_fb.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c
> index d48fd7c918f8..73217c281c9a 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fb.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c
> @@ -145,13 +145,19 @@ struct drm_framebuffer *
> exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
> const struct drm_mode_fb_cmd2 *mode_cmd)
> {
> + const struct drm_format_info *info = drm_get_format_info(dev, mode_cmd);
> struct exynos_drm_gem *exynos_gem[MAX_FB_BUFFER];
> struct drm_gem_object *obj;
> struct drm_framebuffer *fb;
> int i;
> int ret;
>
> - for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) {
> + for (i = 0; i < info->num_planes; i++) {
> + unsigned int height = (i == 0) ? mode_cmd->height :
> + DIV_ROUND_UP(mode_cmd->height, info->vsub);
> + unsigned long size = height * mode_cmd->pitches[i] +
> + mode_cmd->offsets[i];
> +
> obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[i]);
> if (!obj) {
> DRM_ERROR("failed to lookup gem object\n");
> @@ -160,6 +166,12 @@ struct drm_framebuffer *
> }
>
> exynos_gem[i] = to_exynos_gem(obj);
> +
> + if (size > exynos_gem[i]->size) {
> + i++;
> + ret = -EINVAL;
> + goto err;
> + }
> }
>
> fb = exynos_drm_framebuffer_init(dev, mode_cmd, exynos_gem, i);
>