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,URIBL_BLOCKED, 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 468D8ECE58E for ; Tue, 8 Oct 2019 11:02:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1266E2070B for ; Tue, 8 Oct 2019 11:02:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1266E2070B 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 855518E0005; Tue, 8 Oct 2019 07:02:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 805A98E0003; Tue, 8 Oct 2019 07:02:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 741D78E0005; Tue, 8 Oct 2019 07:02:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0238.hostedemail.com [216.40.44.238]) by kanga.kvack.org (Postfix) with ESMTP id 4E8CD8E0003 for ; Tue, 8 Oct 2019 07:02:14 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id E912752B3 for ; Tue, 8 Oct 2019 11:02:13 +0000 (UTC) X-FDA: 76020328146.30.steel29_4d83fe662323a X-HE-Tag: steel29_4d83fe662323a X-Filterd-Recvd-Size: 2414 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Tue, 8 Oct 2019 11:02:12 +0000 (UTC) X-UUID: 814ed363ca79487d969aaa2a5840218c-20191008 X-UUID: 814ed363ca79487d969aaa2a5840218c-20191008 Received: from mtkcas07.mediatek.inc [(172.21.101.84)] by mailgw02.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 2095119737; Tue, 08 Oct 2019 19:02:09 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 8 Oct 2019 19:02:07 +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; Tue, 8 Oct 2019 19:02:07 +0800 Message-ID: <1570532528.4686.102.camel@mtksdccf07> Subject: Re: [PATCH] kasan: fix the missing underflow in memmove and memcpy with CONFIG_KASAN_GENERIC=y From: Walter Wu To: Qian Cai CC: Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Matthias Brugger , LKML , kasan-dev , Linux-MM , Linux ARM , , wsd_upstream Date: Tue, 8 Oct 2019 19:02:08 +0800 In-Reply-To: References: <1570515358.4686.97.camel@mtksdccf07> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.261325, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 2019-10-08 at 05:47 -0400, Qian Cai wrote: >=20 > > On Oct 8, 2019, at 2:16 AM, Walter Wu wro= te: > >=20 > > It is an undefined behavior to pass a negative numbers to > > memset()/memcpy()/memmove(), so need to be detected by KASAN. >=20 > Why can=E2=80=99t this be detected by UBSAN? I don't know very well in UBSAN, but I try to build ubsan kernel and test a negative number in memset and kmalloc_memmove_invalid_size(), it look like no check.