diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 90288ec7c284..3644c94c0a17 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -477,7 +477,9 @@ long drm_ioctl(struct file *filp,
 				retcode = -EFAULT;
 				goto err_i1;
 			}
-		}
+		} else
+			memset(kdata, 0, _IOC_SIZE(cmd));
+
 		if (ioctl->flags & DRM_UNLOCKED)
 			retcode = func(dev, kdata, file_priv);
 		else {