drm: Reject addfb2 with undefined flag bits set

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 3533609..7ac3952 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2331,6 +2331,11 @@
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -EINVAL;
 
+	if (r->flags & ~DRM_MODE_FB_INTERLACED) {
+		DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
+		return -EINVAL;
+	}
+
 	if ((config->min_width > r->width) || (r->width > config->max_width)) {
 		DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
 			  r->width, config->min_width, config->max_width);