static int asymmetric_key_preparse(struct key_preparsed_payload *prep)
{
	struct asymmetric_key_parser *parser;
	int ret;

	pr_devel("==>%s()\n", __func__);

	if (prep->datalen == 0)
		return -EINVAL;

	down_read(&asymmetric_key_parsers_sem);

	ret = -EBADMSG;
	list_for_each_entry(parser, &asymmetric_key_parsers, link) {
		pr_debug("Trying parser '%s'\n", parser->name);

		ret = parser->parse(prep);
		if (ret != -EBADMSG) {
			pr_debug("Parser recognised the format (ret %d)\n",
				 ret);
			break;
		}
	}

	up_read(&asymmetric_key_parsers_sem);
	pr_devel("<==%s() = %d\n", __func__, ret);
	return ret;
}

The product dereferences a pointer that it expects to be valid but is NULL.