fix_drm_getunique_crash.patch

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 73818ff..7ba70ec 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -122,6 +122,12 @@ int drm_getunique(struct drm_device *dev, void *data,
 
 	mutex_lock(&dev->master_mutex);
 	master = file_priv->master;
+
+	if (!master) {
+		mutex_unlock(&dev->master_mutex);
+		return -EINVAL;
+	}
+
 	if (u->unique_len >= master->unique_len) {
 		if (copy_to_user(u->unique, master->unique, master->unique_len)) {
 			mutex_unlock(&dev->master_mutex);