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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B53CBC433E0 for ; Fri, 8 Jan 2021 20:55:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FB3023A7C for ; Fri, 8 Jan 2021 20:55:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729142AbhAHUzM (ORCPT ); Fri, 8 Jan 2021 15:55:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726227AbhAHUzM (ORCPT ); Fri, 8 Jan 2021 15:55:12 -0500 Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A860EC0612EA for ; Fri, 8 Jan 2021 12:54:31 -0800 (PST) Received: by mail-il1-x12f.google.com with SMTP id w17so11561125ilj.8 for ; Fri, 08 Jan 2021 12:54:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=7sDo7Ig6dt2HxHSXD1nx4pPbJPS7gh4sWOn7HUm8xWI=; b=mPDKeANGgH15/xo29DTlSZ1g1TfSRRAiA1k0ZeNe3QrC75e3zQdbqycUodA1PiYhVc hJTv5Ib1bfUQuQC3rbX6dK/SAHGS8alAZz8shYFjF7SlqzKkBEXz0yWrWgqKQ8iIUG7F Ffs8RQGEmU0olqPzxQ74zg+gjIV8XA1hrzmjh2gVgn1hH+dME738NYL3a7j67Iyykvzi qhnUJwwTtxV5LHWFlGLQ9GJ3GkqOdWX2Xxv4krOwVy9CGZOivWAWbhdFCDZFHoANz7/O 1W9bkpR6IXX8Y0VKIEvG3bLb+D+DVwTJnXVdgQAlm/hrWylyTkjIxyhnR9qet3vB3782 EyRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=7sDo7Ig6dt2HxHSXD1nx4pPbJPS7gh4sWOn7HUm8xWI=; b=nPVQtvDxVTq6sQNtUUPPW75PYufZX5v+2/lEFtIRS+RGIdGbia97NWj64g75iozpg9 Si4EIMYiwdYmroq2GLinkjc6rLmr38cpxipI4MMmGYnA8VWh6EyBab2OV8t84rd+1GAn V/nFMV+bVQApOtaUS7oxT8Pi6eCmtryptmYxF7PYum7Je2Y8yxDTih9Q6NbqSgSUM9Oo StZJ+RZisFJ9b0Z8ewyAAentaEP+jtkhplCWJ1EINKsGQElKcw5RkXH0I3+qq4emJpym zkW4GtseaZYp7Ahj6GmJGM42YwQJS3WrjlHKRayvMw8Im2PQyfAYG3fa9DcGzLjbju0b bR/w== X-Gm-Message-State: AOAM533bkKcifhTTVadM5GD+WRPn67fxcU17L4OnTqlQx4lhNTergbPd JsQpeOsBfVqGSOLgpYANfWY= X-Google-Smtp-Source: ABdhPJylezPuqPddhKq1qSotHzhfsK4Y+VoLRyotouG7ekXbb0IBcIiKbO68ddOAgVdVm9pJwnatdg== X-Received: by 2002:a92:77c9:: with SMTP id s192mr5382314ilc.75.1610139270928; Fri, 08 Jan 2021 12:54:30 -0800 (PST) Received: from ubuntu-m3-large-x86 ([2604:1380:45f1:1d00::1]) by smtp.gmail.com with ESMTPSA id z18sm7639133ilb.26.2021.01.08.12.54.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Jan 2021 12:54:30 -0800 (PST) Date: Fri, 8 Jan 2021 13:54:28 -0700 From: Nathan Chancellor To: Dmitry Vyukov Cc: noloader@gmail.com, "Jason A. Donenfeld" , Netdev , syzkaller-bugs , WireGuard mailing list Subject: Re: UBSAN: object-size-mismatch in wg_xmit Message-ID: <20210108205428.GA2547211@ubuntu-m3-large-x86> References: <000000000000e13e2905b6e830bb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Jan 08, 2021 at 10:33:19AM +0100, Dmitry Vyukov wrote: > On Thu, Jan 7, 2021 at 8:06 PM Jeffrey Walton wrote: > > > > On Thu, Jan 7, 2021 at 2:03 PM Jason A. Donenfeld wrote: > > > > > > On Thu, Jan 7, 2021 at 1:22 PM Dmitry Vyukov wrote: > > > > > > > > On Mon, Dec 21, 2020 at 12:23 PM Jason A. Donenfeld wrote: > > > > > > > > > > ... > > > > > > > > These UBSAN checks were just enabled recently. > > > > It's indeed super easy to trigger: 133083 VMs were crashed on this already: > > > > https://syzkaller.appspot.com/bug?extid=8f90d005ab2d22342b6d > > > > So it's one of the top crashers by now. > > > > > > Ahh, makes sense. So it is easily reproducible after all. > > > > > > You're still of the opinion that it's a false positive, right? I > > > shouldn't spend more cycles on this? > > > > You might consider making a test build with -fno-lto in case LTO is > > mucking things up. > > > > Google Posts Patches So The Linux Kernel Can Be LTO-Optimized By > > Clang, https://www.phoronix.com/scan.php?page=news_item&px=Linux-Kernel-Clang-LTO-Patches > > Hi Jeff, > > Are these patches upstream now? > syzbot doesn't enable LTO intentionally, nor I see CONFIG_LTO in the > provided config. Those patches are not upstream yet and LTO will have to be explicitly enabled via config. Cheers, Nathan