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=-9.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 3EED1C433E1 for ; Wed, 15 Jul 2020 15:00:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D4B0206D5 for ; Wed, 15 Jul 2020 15:00:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="dZ1/RMvV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727107AbgGOPAU (ORCPT ); Wed, 15 Jul 2020 11:00:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725980AbgGOPAT (ORCPT ); Wed, 15 Jul 2020 11:00:19 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AC48C08C5DB for ; Wed, 15 Jul 2020 08:00:19 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id e8so3203314pgc.5 for ; Wed, 15 Jul 2020 08:00:19 -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=fR6dbzH+dt2SEyGVkXPzqeJIOxjozyDdDFXnWvcFfX8=; b=dZ1/RMvVMw39VXexb8tF5pKBAs9eG1auhY0F1a3hrpry2k+MwNS+NfYPBJn4l/OyOl MMGxILx7NUe1DtKUCsjo6iqwgNfj8rPmMOE9ImNGsHhvhZ6li/EFGieZMFIn5OpEDXV7 ut4LgorSf+/UYrIkxLpqE1DSUXjPhJWohxSA0= 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=fR6dbzH+dt2SEyGVkXPzqeJIOxjozyDdDFXnWvcFfX8=; b=r8JE3cCJpdYKmtw+Y0am/mI+yGVXZzlM+6ZYXYbW2QdL/lbhvWwV3TIPkQcEv6eTqd XLE59fiZGuxHpc5pVRSpXHBrd7FGX2Y9zDhZN7n6882XdaZ4jKxzKfx+Av6jru7GBI/c 9UnRJcmXeJRD4Ok13PLmTvvbl2qXRx5oMN57JHtV3RREbqg6hJZCkHYFM8ekNh/L5mO1 DahpcrE0I83RehOFye6JKY5QuG7TLmHDWl6R7LTMTZuiRw8eXcm7bUuCeCT4J57ZeQbD UkcxsucCynfEDqwF1jq53qIfcMqt26idRKdiGYt3vzA+zZUS5b0Z0TrAFvjoEV/DAQPo 8qhQ== X-Gm-Message-State: AOAM530LPUIPnp7/fcsWCzS/JsQdT7x2wvJpOfc0mH2OLUoVf6I4x4dI P+EtDhmguJAS0uyVyemnONr8cw== X-Google-Smtp-Source: ABdhPJypnXERMxHttwqG67BS2VGWnOLjufZ/tc6bZRGQt5L3sS8EuZ6AokDXU5Pm9inEKXvID0wnEA== X-Received: by 2002:aa7:9736:: with SMTP id k22mr8906785pfg.62.1594825218717; Wed, 15 Jul 2020 08:00:18 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t1sm2543656pje.55.2020.07.15.08.00.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jul 2020 08:00:17 -0700 (PDT) Date: Wed, 15 Jul 2020 08:00:16 -0700 From: Kees Cook To: Christoph Hellwig Cc: "Eric W. Biederman" , linux-kernel@vger.kernel.org, Linus Torvalds , Andy Lutomirski , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Al Viro , Luis Chamberlain , linux-fsdevel@vger.kernel.org, Tetsuo Handa , linux-security-module@vger.kernel.org, "Serge E. Hallyn" , James Morris , Kentaro Takeda , Casey Schaufler , John Johansen Subject: Re: [PATCH 7/7] exec: Implement kernel_execve Message-ID: <202007150758.3D1597C6D@keescook> References: <871rle8bw2.fsf@x220.int.ebiederm.org> <87wo365ikj.fsf@x220.int.ebiederm.org> <202007141446.A72A4437C@keescook> <20200715064248.GH32470@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200715064248.GH32470@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Jul 15, 2020 at 07:42:48AM +0100, Christoph Hellwig wrote: > On Tue, Jul 14, 2020 at 02:49:23PM -0700, Kees Cook wrote: > > On Tue, Jul 14, 2020 at 08:31:40AM -0500, Eric W. Biederman wrote: > > > +static int count_strings_kernel(const char *const *argv) > > > +{ > > > + int i; > > > + > > > + if (!argv) > > > + return 0; > > > + > > > + for (i = 0; argv[i]; ++i) { > > > + if (i >= MAX_ARG_STRINGS) > > > + return -E2BIG; > > > + if (fatal_signal_pending(current)) > > > + return -ERESTARTNOHAND; > > > + cond_resched(); > > > + } > > > + return i; > > > +} > > > > I notice count() is only ever called with MAX_ARG_STRINGS. Perhaps > > refactor that too? (And maybe rename it to count_strings_user()?) > > Liks this? > > http://git.infradead.org/users/hch/misc.git/commitdiff/35a3129dab5b712b018c30681d15de42d9509731 Heh, yes please. :) (Which branch is this from? Are yours and Eric's tree going to collide?) -- Kees Cook