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=-4.0 required=3.0 tests=BAYES_00, 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 E1AA9C433E7 for ; Wed, 2 Sep 2020 15:36:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9C55208C7 for ; Wed, 2 Sep 2020 15:36:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728402AbgIBPfz (ORCPT ); Wed, 2 Sep 2020 11:35:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728244AbgIBPfx (ORCPT ); Wed, 2 Sep 2020 11:35:53 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D277C061245; Wed, 2 Sep 2020 08:35:53 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDUnK-009LqU-QO; Wed, 02 Sep 2020 15:35:30 +0000 Date: Wed, 2 Sep 2020 16:35:30 +0100 From: Al Viro To: Takashi Iwai Cc: maz@kernel.org, alsa-devel@alsa-project.org, dan.carpenter@oracle.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, o-takashi@sakamocchi.jp, perex@perex.cz, syzkaller-bugs@googlegroups.com, tiwai@suse.com Subject: Re: general protection fault in snd_ctl_release Message-ID: <20200902153530.GK1236603@ZenIV.linux.org.uk> References: <000000000000c15ee205ae4f2531@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Sep 02, 2020 at 05:22:00PM +0200, Takashi Iwai wrote: > Marc, Al, could you guys check this bug? That's racy; the first one should be get_file_rcu() instead of file_count()+get_file(), the second is not needed at all (we have the file pinned down by the caller). See vfs.git#work.epoll for fix