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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8E915C432C0 for ; Mon, 2 Dec 2019 10:23:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6174520718 for ; Mon, 2 Dec 2019 10:23:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726330AbfLBKXc (ORCPT ); Mon, 2 Dec 2019 05:23:32 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2145 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726276AbfLBKXc (ORCPT ); Mon, 2 Dec 2019 05:23:32 -0500 Received: from LHREML710-CAH.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id 7AC43DCEC5967BE6F81D; Mon, 2 Dec 2019 10:23:30 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by LHREML710-CAH.china.huawei.com (10.201.108.33) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 2 Dec 2019 10:23:30 +0000 Received: from [127.0.0.1] (10.202.226.46) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1713.5; Mon, 2 Dec 2019 10:23:29 +0000 Subject: Re: linuxnext-2019127 edac warns (was Re: edac KASAN warning in experimental arm64 allmodconfig boot) To: Robert Richter CC: Borislav Petkov , Mauro Carvalho Chehab , James Morse , "tony.luck@intel.com" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , wanghuiqiang , Xiaofei Tan , Linuxarm , "Huangming (Mark)" References: <304df85b-8b56-b77e-1a11-aa23769f2e7c@huawei.com> <93bdc04e-9e8f-b766-6e97-9fd9e1460a8c@huawei.com> <20191121142302.rhvgkgqpiubidhtu@rric.localdomain> <4ff7631f-fbb7-e45f-87dd-9223beca4da7@huawei.com> <20191122112842.tmf4lkj52hpv6tqd@rric.localdomain> <4c1bd075-75ec-8445-9595-467b88a406b3@huawei.com> <957a809b-9efd-0979-df5d-a4f095da6147@huawei.com> <20191128211240.yuuhf4xkzhl2jvfw@rric.localdomain> From: John Garry Message-ID: <49bb86d8-a7ad-e66d-9796-799ee0bdd605@huawei.com> Date: Mon, 2 Dec 2019 10:23:29 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <20191128211240.yuuhf4xkzhl2jvfw@rric.localdomain> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.46] X-ClientProxiedBy: lhreml702-chm.china.huawei.com (10.201.108.51) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-edac-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org On 28/11/2019 21:12, Robert Richter wrote: > On 27.11.19 17:07:33, John Garry wrote: >> [ 22.104498] BUG: KASAN: use-after-free in >> edac_remove_sysfs_mci_device+0x148/0x180 > > It is triggered in edac_remove_sysfs_mci_device(). > > device_unregister(&dimm->dev) not only removes the sysfs entry, it > also frees the dimm struct in dimm_attr_release(). When incrementing > the loop in mci_for_each_dimm(), the dimm struct is accessed again > which causes the use-after-free. But, the dimm struct shouln'd be > released here already. > > edac_remove_sysfs_mci_device() should not release the devices at this > point. We need clean release functions for mci and dimm_info and > refcounts to protect pdev/dev mappings. And mci_for_each_dimm() must > be checked how it handles device removals and if it is safe. > > Let's see how this can be fixed. > > Thanks for reporting the issue. Fine, and would any fix also deal with the v5.4 mem leak which I mentioned also? Cheers, John