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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 A68F2C2D0BF for ; Tue, 10 Dec 2019 12:46:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85BC62073B for ; Tue, 10 Dec 2019 12:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727385AbfLJMqt (ORCPT ); Tue, 10 Dec 2019 07:46:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:36136 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727131AbfLJMqt (ORCPT ); Tue, 10 Dec 2019 07:46:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 44A83ABC4; Tue, 10 Dec 2019 12:46:47 +0000 (UTC) Date: Tue, 10 Dec 2019 13:46:46 +0100 Message-ID: From: Takashi Iwai To: Lukas Wunner Cc: Nicholas Johnson , "mika.westerberg@linux.intel.com" , Bjorn Helgaas , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , alexander.deucher@amd.com, tiwai@suse.de Subject: Re: Linux v5.5 serious PCI bug In-Reply-To: <20191210122941.zzybs4z5jphpjsu2@wunner.de> References: <20191209131239.GP2665@lahna.fi.intel.com> <20191210072800.GY2665@lahna.fi.intel.com> <20191210122941.zzybs4z5jphpjsu2@wunner.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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 10 Dec 2019 13:29:41 +0100, Lukas Wunner wrote: > > [cc += Alex, Takashi] > > On Tue, Dec 10, 2019 at 12:00:23PM +0000, Nicholas Johnson wrote: > > On Tue, Dec 10, 2019 at 09:28:00AM +0200, mika.westerberg@linux.intel.com wrote: > > > On Mon, Dec 09, 2019 at 01:33:49PM +0000, Nicholas Johnson wrote: > > > > On Mon, Dec 09, 2019 at 03:12:39PM +0200, mika.westerberg@linux.intel.com wrote: > > > > > On Mon, Dec 09, 2019 at 12:34:04PM +0000, Nicholas Johnson wrote: > > > > > > I have compiled Linux v5.5-rc1 and thought all was good until I > > > > > > hot-removed a Gigabyte Aorus eGPU from Thunderbolt. The driver for the > > > > > > GPU was not loaded (blacklisted) so the crash is nothing to do with the > > > > > > GPU driver. > > > > > > > > > > > > We had: > > > > > > - kernel NULL pointer dereference > > > > > > - refcount_t: underflow; use-after-free. > > > > The following is the culprit responsible for the issues: > > > > commit 586bc4aab878efcf672536f0cdec3d04b6990c94 > > Author: Alex Deucher > > Date: Fri Nov 22 16:43:50 2019 -0500 > > > > ALSA: hda/hdmi - fix vgaswitcheroo detection for AMD > > Does the below fix the issue? > > -- >8 -- > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > index 35b4526f0d28..b856b89378ac 100644 > --- a/sound/pci/hda/hda_intel.c > +++ b/sound/pci/hda/hda_intel.c > @@ -1419,7 +1419,6 @@ static bool atpx_present(void) > return true; > } > } > - pci_dev_put(pdev); > } > return false; > } Oh this looks really like a bug, even if this isn't the root cause. Care to submit a proper patch? thanks, Takashi