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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 7286FC433E2 for ; Tue, 14 Jul 2020 21:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5034B206F0 for ; Tue, 14 Jul 2020 21:49:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="OfmVSBDs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727999AbgGNVt0 (ORCPT ); Tue, 14 Jul 2020 17:49:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727021AbgGNVt0 (ORCPT ); Tue, 14 Jul 2020 17:49:26 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9261C061794 for ; Tue, 14 Jul 2020 14:49:25 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id ls15so37811pjb.1 for ; Tue, 14 Jul 2020 14:49:25 -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=z/2Da3iNyWh0eVa9re/PxqTbl8E4lNL39Wvo8BQa5Jk=; b=OfmVSBDsHc9Rmasjt6KXSUQdd+K+htfdnDGZNH60suyaUxoZ6TXC2sZQyckRFbNtVW eCczQAunkP9IdML7SUT1mKGAgRCYJZ2JU2BzFii89fLlf5/fb6WZmg8/bak5hryNE5Y3 stsrls1AUgm02a5MgTkAsfCOzaG5T8ZvxZN3Q= 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=z/2Da3iNyWh0eVa9re/PxqTbl8E4lNL39Wvo8BQa5Jk=; b=pMR/DINa6Fg4EiQPoMTBJ1JEJdQE39kxvJXU97UP/wmQxylLfsiWLPBFWHwM1UCj+Q o4WmsoGwrAL5VTUPFvH2tjNq9KjIMyJ4eqIycoYQ5A0F5d9Cp/YYvaZJdNNg99eUduCr RTLRr3pEMF4E1xRJ36imdgHSXWoaxasTQCD9V43NefAAubwu5yu1cS8mmHUN40hjibCQ 8D3uomrTcX70LN6RZSK2Sy2PZxC+XkAiN0BZj3KtspsJfy1+zFwdkiy3KYEgDObfIW4F wVGlCvswfQFUpJa9coyam+TI8MRvNNSWM0JTHEwGJ2fABVfHYty7taVlWaIfQY88Vl9x ws/g== X-Gm-Message-State: AOAM531TXFZ/LFqB/ePV5ODOrkoRMPXiy/dAjYSbIh9aMCcVRl0JB6Wv TIER8ezXlNJ3tctILokmVG+nOA== X-Google-Smtp-Source: ABdhPJyfHN6nndxTZkr0qhDNx67iZO+T5mcaIl+et4AYLVpGCPX9K8cfoszp9wO2zi7jQoRkZbuhYA== X-Received: by 2002:a17:90a:240a:: with SMTP id h10mr7042196pje.225.1594763365288; Tue, 14 Jul 2020 14:49:25 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id br9sm48405pjb.56.2020.07.14.14.49.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jul 2020 14:49:24 -0700 (PDT) Date: Tue, 14 Jul 2020 14:49:23 -0700 From: Kees Cook To: "Eric W. Biederman" Cc: 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 , Christoph Hellwig Subject: Re: [PATCH 7/7] exec: Implement kernel_execve Message-ID: <202007141446.A72A4437C@keescook> References: <871rle8bw2.fsf@x220.int.ebiederm.org> <87wo365ikj.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87wo365ikj.fsf@x220.int.ebiederm.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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()?) Otherwise, looks good: Reviewed-by: Kees Cook -- Kees Cook