nextcloud-server/core/img/actions/upload-white.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://www.w3.org/2000/svg" height="16" width="16" version="1.1" xmlns:cc="http://creativecommons.org/ns#" xmlns:dc="http://purl.org/dc/elements/1.1/">
 <path fill="#fff" d="m8 1-6 6h4v4h4v-4h4zm-6 12v2h12v-2z"/>
</svg>