diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index f49f870..53154a6 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -279,8 +279,10 @@ static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 	struct usb_request *req = ffs->ep0req;
 	int ret;
 
-	if (!req)
+	if (!req) {
+		spin_unlock_irq(&ffs->ev.waitq.lock);
 		return -EINVAL;
+	}
 
 	req->zero     = len < le16_to_cpu(ffs->ev.setup.wLength);