From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E24CC43144 for ; Mon, 25 Jun 2018 22:23:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 39DF3261A7 for ; Mon, 25 Jun 2018 22:23:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 39DF3261A7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754530AbeFYWXM (ORCPT ); Mon, 25 Jun 2018 18:23:12 -0400 Received: from smtprelay0224.hostedemail.com ([216.40.44.224]:36699 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752363AbeFYWXK (ORCPT ); Mon, 25 Jun 2018 18:23:10 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay03.hostedemail.com (Postfix) with ESMTP id C409A837F24C; Mon, 25 Jun 2018 22:23:09 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: force06_384f1d4000049 X-Filterd-Recvd-Size: 1443 Received: from XPS-9350.home (unknown [47.151.150.235]) (Authenticated sender: joe@perches.com) by omf07.hostedemail.com (Postfix) with ESMTPA; Mon, 25 Jun 2018 22:23:06 +0000 (UTC) Message-ID: Subject: Re: [PATCH v3 net-next] mdio-mux-gpio: Remove VLA usage From: Joe Perches To: Kees Cook , "David S. Miller" Cc: linux-kernel@vger.kernel.org, Andrew Lunn , netdev@vger.kernel.org Date: Mon, 25 Jun 2018 15:23:05 -0700 In-Reply-To: <20180625220917.GA25022@beast> References: <20180625220917.GA25022@beast> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-06-25 at 15:09 -0700, Kees Cook wrote: > In the quest to remove all stack VLA usage from the kernel[1], this > allocates the values buffer during the callback instead of putting it > on the stack. [] > diff --git a/drivers/net/phy/mdio-mux-gpio.c b/drivers/net/phy/mdio-mux-gpio.c [] > @@ -44,15 +44,21 @@ static int mdio_mux_gpio_switch_fn(int current_child, int desired_child, > static int mdio_mux_gpio_probe(struct platform_device *pdev) > { [] > + s = devm_kzalloc(&pdev->dev, sizeof(*s->values) * gpios->ndescs + > + sizeof(*s), GFP_KERNEL); Isn't this supposed to use your new struct_size()