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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 9EC19C282DA for ; Wed, 17 Apr 2019 03:21:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D8A820835 for ; Wed, 17 Apr 2019 03:21:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="KxEJeVgs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729689AbfDQDVc (ORCPT ); Tue, 16 Apr 2019 23:21:32 -0400 Received: from mail-ua1-f68.google.com ([209.85.222.68]:44573 "EHLO mail-ua1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727618AbfDQDVb (ORCPT ); Tue, 16 Apr 2019 23:21:31 -0400 Received: by mail-ua1-f68.google.com with SMTP id p13so7425652uaa.11 for ; Tue, 16 Apr 2019 20:21:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yKezm9r0olp54QGM5Hm5rJdwgLUK004Edlxk2j2pDwY=; b=KxEJeVgs0D8A1NkmLJaSkhnxrveRReA2blDNjCSR50u6qGIzZg4JJWN7GW9MdWT4kZ mSSE+bNIIGw2CAKRlHqruQZ9Vwr4lZWE6Yj9SDOZCL/3YAPsDrXA0fI+uQEVvGa230X7 THhJwq+/j62qKOycT+Y6+zwYAU3R/zWgkkQDg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yKezm9r0olp54QGM5Hm5rJdwgLUK004Edlxk2j2pDwY=; b=Dfa+5jghyyI3UZV9DoWDB8WZW3AGuscq+JgmQaPvxDrxKTEIGstL7Pc34iu18nwGKA bKxdIE46R9hG30VMPQpk4Mr8PmQRml3ggNLJ5IZDMEWNPHfzHrx5A7rzbwHVaj95DsjM tIklG/qPwwq5++xLto2pntps2FB/0tg+cvOBmKeGsXDeHsYoGbyW44YWthITMnMRBmKq Ea5uQNgr8iBwDXr2Bi5Jp47kSBMLJ7754RgFHap19pBnj96IslQ1DO9ln28hRpijME8l ZhiOIFTaiK8oYOuLlbRIIYbcESL/J8brzbGdfE0TiLvG1jSDDdgGXi+a9UCyj9Cg6atB YePA== X-Gm-Message-State: APjAAAUzm/Mc9uL+hVys/4js4wwx0er0CErejNnZbVI1+KyLJeylpP8O HCbYpEYO1SQlYFF4kOvEyxHNpU8wNhc= X-Google-Smtp-Source: APXvYqwMHuAjXalab2z4yJ7bQMPbW1NxDpHBWvHVKFxBUfi55V8bPWr2WV4Q8p1MsQLamZ3fcbyk+g== X-Received: by 2002:ab0:340a:: with SMTP id z10mr36055578uap.10.1555471289940; Tue, 16 Apr 2019 20:21:29 -0700 (PDT) Received: from mail-vk1-f179.google.com (mail-vk1-f179.google.com. [209.85.221.179]) by smtp.gmail.com with ESMTPSA id y1sm57914714uai.0.2019.04.16.20.21.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Apr 2019 20:21:28 -0700 (PDT) Received: by mail-vk1-f179.google.com with SMTP id o187so4910259vkg.4 for ; Tue, 16 Apr 2019 20:21:28 -0700 (PDT) X-Received: by 2002:a1f:29c5:: with SMTP id p188mr46643241vkp.24.1555471288313; Tue, 16 Apr 2019 20:21:28 -0700 (PDT) MIME-Version: 1.0 References: <20190408220925.13077-1-mcroce@redhat.com> <20190408220925.13077-3-mcroce@redhat.com> In-Reply-To: <20190408220925.13077-3-mcroce@redhat.com> From: Kees Cook Date: Tue, 16 Apr 2019 22:21:16 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 2/2] kernel: use sysctl shared variables for range check To: Matteo Croce Cc: LKML , "linux-fsdevel@vger.kernel.org" , Luis Chamberlain , Kees Cook , Alexey Dobriyan Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Apr 8, 2019 at 5:09 PM Matteo Croce wrote: > > Use the shared variables for range check, instead of declaring a local one > in every source file. > > Signed-off-by: Matteo Croce > --- > kernel/pid_namespace.c | 3 +- > kernel/sysctl.c | 193 ++++++++++++++++++++--------------------- > kernel/ucount.c | 6 +- > 3 files changed, 98 insertions(+), 104 deletions(-) > > diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c > index aa6e72fb7c08..ddbb51bc4968 100644 > --- a/kernel/pid_namespace.c > +++ b/kernel/pid_namespace.c > @@ -290,14 +290,13 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write, > } > > extern int pid_max; > -static int zero = 0; > static struct ctl_table pid_ns_ctl_table[] = { > { > .procname = "ns_last_pid", > .maxlen = sizeof(int), > .mode = 0666, /* permissions are checked in the handler */ > .proc_handler = pid_ns_ctl_handler, > - .extra1 = &zero, > + .extra1 = (void *)&sysctl_zero, BTW, I don't think these (void *) casts are actually needed. I thought extra1/2 were already void * so assignments don't need the casting. -- Kees Cook