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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_2 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 968ABECE587 for ; Mon, 14 Oct 2019 15:57:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 63CF720873 for ; Mon, 14 Oct 2019 15:57:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63CF720873 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0EABB8E0005; Mon, 14 Oct 2019 11:57:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 09BFB8E0001; Mon, 14 Oct 2019 11:57:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ECC118E0005; Mon, 14 Oct 2019 11:57:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id CCE8D8E0001 for ; Mon, 14 Oct 2019 11:57:21 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 6CC321EE6 for ; Mon, 14 Oct 2019 15:57:21 +0000 (UTC) X-FDA: 76042844682.04.gold79_5d2749ae47f3e X-HE-Tag: gold79_5d2749ae47f3e X-Filterd-Recvd-Size: 2461 Received: from mailgw01.mediatek.com (unknown [210.61.82.183]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Mon, 14 Oct 2019 15:57:19 +0000 (UTC) X-UUID: 82e2e07d42c8401c9fe66a906d53cd58-20191014 X-UUID: 82e2e07d42c8401c9fe66a906d53cd58-20191014 Received: from mtkcas07.mediatek.inc [(172.21.101.84)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 1492891351; Mon, 14 Oct 2019 23:57:12 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Mon, 14 Oct 2019 23:57:10 +0800 Received: from [172.21.84.99] (172.21.84.99) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Mon, 14 Oct 2019 23:57:08 +0800 Message-ID: <1571068631.8898.8.camel@mtksdccf07> Subject: Re: [PATCH 2/2] kasan: add test for invalid size in memmove From: Walter Wu To: Matthew Wilcox CC: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Matthias Brugger , , , , , , Date: Mon, 14 Oct 2019 23:57:11 +0800 In-Reply-To: <20191014150710.GY32665@bombadil.infradead.org> References: <20191014103654.17982-1-walter-zh.wu@mediatek.com> <20191014150710.GY32665@bombadil.infradead.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N X-Bogosity: Ham, tests=bogofilter, spamicity=0.051833, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 2019-10-14 at 08:07 -0700, Matthew Wilcox wrote: > On Mon, Oct 14, 2019 at 06:36:54PM +0800, Walter Wu wrote: > > Test size is negative numbers in memmove in order to verify > > whether it correctly get KASAN report. > > You're not testing negative numbers, though. memmove() takes an unsigned > type, so you're testing a very large number. > Casting negative numbers to size_t would indeed turn up as a "large" size_t and its value will be larger than ULONG_MAX/2. We mainly want to express this case. Maybe we can add some descriptions. Thanks for your reminder.