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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 77B7FC433E7 for ; Thu, 15 Oct 2020 08:23:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C04C522250 for ; Thu, 15 Oct 2020 08:23:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C04C522250 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id F284C6B0062; Thu, 15 Oct 2020 04:23:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ED9C96B0070; Thu, 15 Oct 2020 04:23:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DEDD06B0071; Thu, 15 Oct 2020 04:23:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0250.hostedemail.com [216.40.44.250]) by kanga.kvack.org (Postfix) with ESMTP id AC42A6B0062 for ; Thu, 15 Oct 2020 04:23:34 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 360B68249980 for ; Thu, 15 Oct 2020 08:23:34 +0000 (UTC) X-FDA: 77373470748.07.dime44_5d1178d27213 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 0D1491803F9A4 for ; Thu, 15 Oct 2020 08:23:34 +0000 (UTC) X-HE-Tag: dime44_5d1178d27213 X-Filterd-Recvd-Size: 2165 Received: from gentwo.org (gentwo.org [3.19.106.255]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Oct 2020 08:23:33 +0000 (UTC) Received: by gentwo.org (Postfix, from userid 1002) id 1529E3F0EE; Thu, 15 Oct 2020 08:23:33 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 12ACA3F042; Thu, 15 Oct 2020 08:23:33 +0000 (UTC) Date: Thu, 15 Oct 2020 08:23:33 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Kees Cook cc: Andrew Morton , Vlastimil Babka , Waiman Long , Marco Elver , Pekka Enberg , David Rientjes , Joonsoo Kim , Roman Gushchin , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 0/3] Actually fix freelist pointer vs redzoning In-Reply-To: <20201015033712.1491731-1-keescook@chromium.org> Message-ID: References: <20201015033712.1491731-1-keescook@chromium.org> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 14 Oct 2020, Kees Cook wrote: > Note on patch 2: Christopher NAKed it, but I actually think this is a > reasonable thing to add -- the "too small" check is only made when built > with CONFIG_DEBUG_VM, so it *is* actually possible for someone to trip > over this directly, even if it would never make it into a released > kernel. I see no reason to just leave this foot-gun in place, though, so > we might as well just fix it too. (Which seems to be what Longman was > similarly supporting, IIUC.) Well then remove the duplication of checks. The NAK was there because it seems that you were not aware of the existing checks. > Anyway, if patch 2 stays NAKed, that's fine. It's entirely separable, > and the other 2 can land. :) Just deal with the old checks too and it will be fine.