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_2 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 F25CBC3A5A0 for ; Mon, 19 Aug 2019 12:37:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95EB62085A for ; Mon, 19 Aug 2019 12:37:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726852AbfHSMhw (ORCPT ); Mon, 19 Aug 2019 08:37:52 -0400 Received: from mx2.suse.de ([195.135.220.15]:38034 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726594AbfHSMhw (ORCPT ); Mon, 19 Aug 2019 08:37:52 -0400 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 C6021AB9B; Mon, 19 Aug 2019 12:37:50 +0000 (UTC) Message-ID: <1566218263.5663.22.camel@suse.com> Subject: Re: divide error in usbtmc_generic_read From: Oliver Neukum To: Andrey Konovalov Cc: syzkaller-bugs , steve_bayless@keysight.com, Greg Kroah-Hartman , guido.kiener@rohde-schwarz.com, syzbot , USB list Date: Mon, 19 Aug 2019 14:37:43 +0200 In-Reply-To: References: <000000000000a59094059013dd63@google.com> <1565875886.5780.7.camel@suse.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Am Montag, den 19.08.2019, 14:17 +0200 schrieb Andrey Konovalov: > On Thu, Aug 15, 2019 at 3:31 PM Oliver Neukum wrote: > > > > Am Mittwoch, den 14.08.2019, 06:38 -0700 schrieb syzbot: > > > syzbot has tested the proposed patch but the reproducer still triggered > > > crash: > > > KASAN: use-after-free Read in usbtmc_disconnect > > > > I am afraid that is a difficiency in KASAN that should be fixed. > > Is the class of the error compared if I leave in more of the > > original bug report? Actually the ID is still there, so it really > > should return an inconclusive in these cases. > > I don't get this, what kind of deficiency do you mean? The original error was a divide by zero. The first fix fixed that but still another error showed up. If I propose a fix there are other possibilities besides it working. I could have no effect on the original bug or my fix breaks something else and KASAN is making no difference between those cases. Regards Oliver