drm/exynos: forbid creating framebuffers from too small GEM buffers

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@samsung.com>
Reviewed-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
This commit is contained in:
Marek Szyprowski 2017-07-12 12:09:22 +02:00 committed by Inki Dae
parent 5669b9989e
commit 1899bd5757

View File

@ -145,13 +145,19 @@ static 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 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
}
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);