diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index a75ca63deea6..0e27d98b2b9f 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -470,7 +470,9 @@ int drm_ioctl(struct inode *inode, struct file *filp,
 				retcode = -EFAULT;
 				goto err_i1;
 			}
-		}
+		} else
+			memset(kdata, 0, _IOC_SIZE(cmd));
+
 		retcode = func(dev, kdata, file_priv);
 
 		if (cmd & IOC_OUT) {