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=0.1 required=3.0 tests=DATE_IN_PAST_03_06, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2FE9EC06511 for ; Wed, 3 Jul 2019 01:03:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 064812089C for ; Wed, 3 Jul 2019 01:03:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562115795; bh=JSSTummgovKzjJ78cGvRjxWkWBFR6+oqkDGCqnix+5g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=lCptYPMnMqIl3CTCLQ4nsy1Z+jOuZfblK96gm8NqypvafRCajSOFadyAQqYOl+C5V tUk176Gtr7ra9Lgd0slC84IGvjZQS5IKfuM+GR+ko2VrZ+SSSJz+cjcyce9qLtDOuK IVWTdfGCzFz3yaU/rwAl5U/YaUaYRcZUNfr+zPxU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727316AbfGCBDF (ORCPT ); Tue, 2 Jul 2019 21:03:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:51750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726652AbfGCBDF (ORCPT ); Tue, 2 Jul 2019 21:03:05 -0400 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BF65A21874; Tue, 2 Jul 2019 20:13:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562098428; bh=JSSTummgovKzjJ78cGvRjxWkWBFR6+oqkDGCqnix+5g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pVL9BX1mfkWNMZ4JuOXEP1bLnhu3I9BVToumxa1kjdZNRBH56OgKPIrtlVhivYmCX ByFpnYvXObta8eYhxDF+YD3vem2AyauZtEzCHZHVRal/nPjba1ZSg4n+ipbJJB+Ury uo7TwFjCDC96bjssFiG+pA6PpZbeBceSeH91LZd4= Date: Tue, 2 Jul 2019 13:13:48 -0700 From: Andrew Morton To: Matteo Croce Cc: Alexey Dobriyan , LKML , Kees Cook , Aaron Tomlin Subject: Re: [PATCH] proc/sysctl: add shared variables for range check Message-Id: <20190702131348.9004db6da7e1cbeb7db5ca9f@linux-foundation.org> In-Reply-To: References: <20190702170228.GA4404@avx2> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2 Jul 2019 19:21:33 +0200 Matteo Croce wrote: > On Tue, Jul 2, 2019 at 7:13 PM Alexey Dobriyan wrote: > > > > > -static long zero; > > > static long long_max = LONG_MAX; > > > > > > struct ctl_table epoll_table[] = { > > > @@ -301,7 +300,7 @@ struct ctl_table epoll_table[] = { > > > .maxlen = sizeof(max_user_watches), > > > .mode = 0644, > > > .proc_handler = proc_doulongvec_minmax, > > > - .extra1 = &zero, > > > + .extra1 = SYSCTL_ZERO, > > > .extra2 = &long_max, > > > > This looks wrong: proc_doulongvec_minmax() expects "long"s. > > The whole patch needs rechecking. > > > > > +/* shared constants to be used in various sysctls */ > > > +const =======>int<========== sysctl_vals[] = { 0, 1, INT_MAX }; > > > +EXPORT_SYMBOL(sysctl_vals); > > Yes, you're right, that chunk must be dropped. > Anyway I've checked the patch, this was the only long field touched. Yup. akpm3:/usr/src/25> find . -name "*.c" | xargs grep -C4 SYSCTL_ZERO|grep long ./fs/eventpoll.c- .proc_handler = proc_doulongvec_minmax, ./fs/eventpoll.c- .extra2 = &long_max, I did this: --- a/fs/eventpoll.c~proc-sysctl-add-shared-variables-for-range-check-fix-4 +++ a/fs/eventpoll.c @@ -291,6 +291,7 @@ static LIST_HEAD(tfile_check_list); #include +static long long_zero; static long long_max = LONG_MAX; struct ctl_table epoll_table[] = { @@ -300,7 +301,7 @@ struct ctl_table epoll_table[] = { .maxlen = sizeof(max_user_watches), .mode = 0644, .proc_handler = proc_doulongvec_minmax, - .extra1 = SYSCTL_ZERO, + .extra1 = &long_zero, .extra2 = &long_max, }, { } I renamed it to avoid using "&zero," in this situation.