drm: Be more paranoid with integer overflows

Make sure 'width * cpp' and 'height * pitch + offset' don't exceed
UINT_MAX.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index ef1b22144d37..d9a639c870f4 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2280,13 +2280,21 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 
         for (i = 0; i < num_planes; i++) {
                 unsigned int width = r->width / (i != 0 ? hsub : 1);
+                unsigned int height = r->height / (i != 0 ? vsub : 1);
+                unsigned int cpp = drm_format_plane_cpp(r->pixel_format, i);
 
                 if (!r->handles[i]) {
                         DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
                         return -EINVAL;
                 }
 
-                if (r->pitches[i] < drm_format_plane_cpp(r->pixel_format, i) * width) {
+                if ((uint64_t) width * cpp > UINT_MAX)
+                        return -ERANGE;
+
+                if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
+                        return -ERANGE;
+
+                if (r->pitches[i] < width * cpp) {
                         DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
                         return -EINVAL;
                 }