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=-2.3 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 CCE84C433FF for ; Mon, 29 Jul 2019 13:36:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A31342070D for ; Mon, 29 Jul 2019 13:36:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387769AbfG2NgW (ORCPT ); Mon, 29 Jul 2019 09:36:22 -0400 Received: from foss.arm.com ([217.140.110.172]:44430 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387722AbfG2NgW (ORCPT ); Mon, 29 Jul 2019 09:36:22 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D2C5328; Mon, 29 Jul 2019 06:36:21 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CFB1E3F71F; Mon, 29 Jul 2019 06:36:20 -0700 (PDT) Date: Mon, 29 Jul 2019 14:36:18 +0100 From: Catalin Marinas To: Dmitry Vyukov Cc: syzkaller , LKML , Tetsuo Handa , Eric Biggers , Eric Dumazet Subject: Re: syzbot bisection analysis Message-ID: <20190729133618.GG2368@arrakis.emea.arm.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dmitry, On Mon, Jul 29, 2019 at 01:08:16PM +0200, Dmitry Vyukov wrote: > The remaining 10 were all diverged due to other unrelated memory leaks > and other non-leak bugs. It seems the main 2 reasons for this: > 1. Lots of leaks are old (kernel is under-tested with KMEMLEAK). > 2. Lots of unrelated bugs. > It's unclear how much KMEMLEAK potential for false positives is in > play. For example, lots of bisections are diverged by "memory leak in > batadv_tvlv_handler_register", but this is a true bug reported at: > https://syzkaller.appspot.com/bug?id=0654529ad3cc1d67a6d9812d8b75489c03dfb983 > However, some are diverged by e.g. "memory leak in __neigh_create" and > "memory leak in copy_process" and these were not reported as separate > leaks, so either false positives or true leaks fixed in previous > releases. Out of curiosity, when the tool tries to bisect a memory leak, does it check for precisely that leak (e.g. by function name, object size) or any other unrelated leak can confuse the bisection? -- Catalin