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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EBD50C2BB40 for ; Tue, 8 Dec 2020 20:26:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDC4523A7B for ; Tue, 8 Dec 2020 20:26:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729404AbgLHU0V (ORCPT ); Tue, 8 Dec 2020 15:26:21 -0500 Received: from mx2.suse.de ([195.135.220.15]:52260 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728685AbgLHU0O (ORCPT ); Tue, 8 Dec 2020 15:26:14 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A6A90AC55; Tue, 8 Dec 2020 20:25:32 +0000 (UTC) Date: Tue, 08 Dec 2020 21:25:32 +0100 Message-ID: From: Takashi Iwai To: Greg Kroah-Hartman Cc: "Rafael J . Wysocki" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] driver: core: Fix list corruption after device_del() In-Reply-To: References: <20201208190326.27531-1-tiwai@suse.de> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 08 Dec 2020 20:52:34 +0100, Greg Kroah-Hartman wrote: > > On Tue, Dec 08, 2020 at 08:03:26PM +0100, Takashi Iwai wrote: > > The device_links_purge() function (called from device_del()) tries to > > remove the links.needs_suppliers list entry, but it's using > > list_del(), hence it doesn't initialize after the removal. This is OK > > for normal cases where device_del() is called via device_destroy(). > > However, it's not guaranteed that the device object will be really > > deleted soon after device_del(). In a minor case like HD-audio codec > > reconfiguration that re-initializes the device after device_del(), it > > may lead to a crash by the corrupted list entry. > > > > As a simple fix, replace list_del() with list_del_init() in order to > > make the list intact after the device_del() call. > > > > Fixes: e2ae9bcc4aaa ("driver core: Add support for linking devices during device addition") > > Cc: > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209207 > > Signed-off-by: Takashi Iwai > > --- > > drivers/base/core.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/base/core.c b/drivers/base/core.c > > index d661ada1518f..e8cb66093f21 100644 > > --- a/drivers/base/core.c > > +++ b/drivers/base/core.c > > @@ -1386,7 +1386,7 @@ static void device_links_purge(struct device *dev) > > return; > > > > mutex_lock(&wfs_lock); > > - list_del(&dev->links.needs_suppliers); > > + list_del_init(&dev->links.needs_suppliers); > > mutex_unlock(&wfs_lock); > > Can this wait until 5.11-rc1 and then get backported, as it has been > around for a while, or are you hitting this on 5.10-rc7 now and need > this for 5.10-final? This is rather a minor (but long-standing) issue, so no problem to wait for 5.11. thanks, Takashi