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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 7B4D9C433B4 for ; Thu, 13 May 2021 06:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36AF8613E6 for ; Thu, 13 May 2021 06:21:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231299AbhEMGW4 (ORCPT ); Thu, 13 May 2021 02:22:56 -0400 Received: from smtp09.smtpout.orange.fr ([80.12.242.131]:54505 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230230AbhEMGWz (ORCPT ); Thu, 13 May 2021 02:22:55 -0400 Received: from [192.168.1.18] ([86.243.172.93]) by mwinf5d84 with ME id 46Mh2500H21Fzsu036MiWh; Thu, 13 May 2021 08:21:44 +0200 X-ME-Helo: [192.168.1.18] X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Thu, 13 May 2021 08:21:44 +0200 X-ME-IP: 86.243.172.93 Subject: Re: [PATCH] net: mdio: Fix a double free issue in the .remove function To: Andrew Lunn Cc: hkallweit1@gmail.com, linux@armlinux.org.uk, davem@davemloft.net, kuba@kernel.org, david.daney@cavium.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org References: From: Christophe JAILLET Message-ID: <6ff7d862-b88a-eea0-d977-b7f71176c5ed@wanadoo.fr> Date: Thu, 13 May 2021 08:21:41 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Le 12/05/2021 à 23:44, Andrew Lunn a écrit : > On Wed, May 12, 2021 at 11:35:38PM +0200, Christophe JAILLET wrote: >> 'bus->mii_bus' have been allocated with 'devm_mdiobus_alloc_size()' in the >> probe function. So it must not be freed explicitly or there will be a >> double free. > > Hi Christophe > > [PATCH] net: mdio: Fix a double free issue in the .remove function > > Please indicate in the subject which mdio bus driver has a double > free. Ok, will do. But looking at [1], it was not not self-explanatory that it was the rule here :) > > Also, octeon_mdiobus_remove() appears to have the same problem. In fact, even a little worse. It also calls 'mdiobus_free()' in the error handling path of the probe (which is why my coccinelle script didn't spot it. It looks for discrepancy between error handling path in the probe and the remove function. If both are wrong, it looks safe :) ) I'll send another patch for this driver. CJ > > Andrew > [1]: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/drivers/net/mdio