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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 4D88DC433B4 for ; Tue, 27 Apr 2021 16:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19D27613EA for ; Tue, 27 Apr 2021 16:15:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237598AbhD0QQL (ORCPT ); Tue, 27 Apr 2021 12:16:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:44954 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237503AbhD0QMM (ORCPT ); Tue, 27 Apr 2021 12:12:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B0F10613E7; Tue, 27 Apr 2021 16:11:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619539888; bh=sWfj4/YD88XWP9TQDYozP4U5HS1T7QaBgPwNmFATYlU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=o/h88WMzn2Ywa8/GnKK3jD2ZlBO2/j1LOTfWQgTjEPBBkT4eyKI/wwEltGRpRePzC vCM5/OsTz8kNQZxkdocoiwlmHts4u1jeeM9lMnhOEupaiEnSRYVO9QXfHwAvnd+SDR fUoD5mTKkuDUCstHbVcxug8Q8se//4XkI04Qqpds= Date: Tue, 27 Apr 2021 18:11:24 +0200 From: Greg KH To: Peter Rosin Cc: Jens Axboe , linux-kernel@vger.kernel.org Subject: Re: [PATCH 167/190] Revert "gdrom: fix a memory leak bug" Message-ID: References: <20210421130105.1226686-168-gregkh@linuxfoundation.org> <23ffd3c5-0095-6a95-8c30-2b6f67377ce7@axentia.se> <14bdfbee-b8b9-d8ac-de34-b6d852d1485b@kernel.dk> <5a55e8d4-e9b6-1854-51bc-afacd3ca097c@axentia.se> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5a55e8d4-e9b6-1854-51bc-afacd3ca097c@axentia.se> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 27, 2021 at 04:03:01PM +0200, Peter Rosin wrote: > On 2021-04-27 15:01, Greg KH wrote: > > On Fri, Apr 23, 2021 at 08:20:30AM -0600, Jens Axboe wrote: > >> On 4/22/21 3:29 PM, Peter Rosin wrote: > >>>> This reverts commit 093c48213ee37c3c3ff1cf5ac1aa2a9d8bc66017. > >>> > >>> The reverted patch looks fishy. > >>> > >>> gc.cd_info is kzalloc:ed on probe. In case probe fails after this allocation, the > >>> memory is kfree:d but the variable is NOT zeroed out. > >>> > >>> AFAICT, the above leads to a double-free on exit by the added line. > >>> > >>> I believe gd.cd_info should be kfree:d on remove instead. > >>> > >>> However, might not gc.toc also be kfree:d twice for similar reasons? > >>> > >>> I could easily be mistaken. > >> > >> >From taking a quick look the other day, that's my conclusion too. I > >> don't think the patch is correct, but I don't think the surrounding code > >> is correct right now either. > > > > Thanks for the review from both of you, I'll keep this commit in the > > tree. > Err, which commit is "this" and what tree are you keeping it in? I > think you mean that you are keeping the revert in your tree with > reverts, and not that you mean that we should keep the original > commit in Linus' tree. That is correct, I will be keeping this revert in my tree. > In any case, I'd think that the original memory leak is somewhat > better than the introduced double-free and therefore the revert > should be done. Will do that. thanks, greg k-h