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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 F0B44C43613 for ; Thu, 20 Jun 2019 17:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCFCC206BA for ; Thu, 20 Jun 2019 17:35:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="NUMqYmFw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726562AbfFTRf7 (ORCPT ); Thu, 20 Jun 2019 13:35:59 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:33711 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726526AbfFTRf7 (ORCPT ); Thu, 20 Jun 2019 13:35:59 -0400 Received: by mail-pg1-f196.google.com with SMTP id m4so1339968pgk.0 for ; Thu, 20 Jun 2019 10:35:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Y//CKAUCmu4Z+CNgNicaVzKkv82IaCbCxrJa7F0wZn4=; b=NUMqYmFwkS8LkBdwNC20JWMzkawUchAYdEs+GIDQku+8JYDBs4GvrjFoeC5g9ptLB5 6iDEHv//HyfEmC5eWmq/MRx0SWCEZ5mvOkbHQvhTphicSrniBya/z8l+GY/YvzCKxgYy 4uSTgSW5ItQ0Slt9KpB8W7gwtPv0WmGfiEtOU= 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=Y//CKAUCmu4Z+CNgNicaVzKkv82IaCbCxrJa7F0wZn4=; b=SfFndbNJlEGuM2lB9wESUpvzU2gU8g8nz6VSFQaIasl+IaUvfUY9Z/Morho2J3jaQl kjYZ2pGNDvDN8Hls3A6k3FbSuFiB8Hoj5Z0yyesU7Vzixcq6vdrdXWI1k0MojuUeHfrc Sx4Gj++zP1zqRjfWUoWhfsGjR1YYdmt+3fregJjTL0uwNljbLdzB0m6M1xgi4MZK6Pdo 14aISUkM+Zo3Sv5goLQ4EY2133kbfnuC8uFSxw9ufvlQWF7xqCvHuWzHzYrDZpcAEh8S PUyJHWmN7NQzE7A0Qd9MIDbZX0OTpeW384XUt5TwB2V5/f/QkxWwkk092GJam7QekR6d nURA== X-Gm-Message-State: APjAAAWe3/1e0g5gRDkp28ZoykmKRHqj+MYph+QoxBy1jk6Hh6LoYLdu p74j7DPTvFpevPDMQYQzKZ5uRQ== X-Google-Smtp-Source: APXvYqxiL8EXgij8EVUiiz93r2xVAl4pTaySQemAPFQP6yna6EQozFcR2qsIBQ9qPplMpsgaKHVBCg== X-Received: by 2002:aa7:8083:: with SMTP id v3mr54261815pff.69.1561052158492; Thu, 20 Jun 2019 10:35:58 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id 128sm89983pfd.66.2019.06.20.10.35.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 20 Jun 2019 10:35:57 -0700 (PDT) Date: Thu, 20 Jun 2019 10:35:56 -0700 From: Kees Cook To: Arnd Bergmann Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, Alexander Popov , Ard Biesheuvel , James Morris , "Serge E. Hallyn" , Masahiro Yamada , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] structleak: disable BYREF_ALL in combination with KASAN_STACK Message-ID: <201906201034.9E44D8A2A8@keescook> References: <20190618094731.3677294-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190618094731.3677294-1-arnd@arndb.de> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Tue, Jun 18, 2019 at 11:47:13AM +0200, Arnd Bergmann wrote: > The combination of KASAN_STACK and GCC_PLUGIN_STRUCTLEAK_BYREF_ALL > leads to much larger kernel stack usage, as seen from the warnings > about functions that now exceed the 2048 byte limit: Is the preference that this go into v5.2 (there's not much time left), or should this be v5.3? (You didn't mark it as Cc: stable?) > one. I picked the dependency in GCC_PLUGIN_STRUCTLEAK_BYREF_ALL, as > this option is designed to make uninitialized stack usage less harmful > when enabled on its own, but it also prevents KASAN from detecting those > cases in which it was in fact needed. Right -- there's not much sense in both being enabled. I'd agree with this rationale. -- Kees Cook