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=-1.0 required=3.0 tests=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 BE1F1C433DF for ; Sun, 21 Jun 2020 17:56:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A18792474A for ; Sun, 21 Jun 2020 17:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730533AbgFUR4j (ORCPT ); Sun, 21 Jun 2020 13:56:39 -0400 Received: from mail.parknet.co.jp ([210.171.160.6]:38404 "EHLO mail.parknet.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730485AbgFUR4j (ORCPT ); Sun, 21 Jun 2020 13:56:39 -0400 X-Greylist: delayed 352 seconds by postgrey-1.27 at vger.kernel.org; Sun, 21 Jun 2020 13:56:38 EDT Received: from ibmpc.myhome.or.jp (server.parknet.ne.jp [210.171.168.39]) by mail.parknet.co.jp (Postfix) with ESMTPSA id 222D515F925; Mon, 22 Jun 2020 02:50:46 +0900 (JST) Received: from devron.myhome.or.jp (foobar@devron.myhome.or.jp [192.168.0.3]) by ibmpc.myhome.or.jp (8.15.2/8.15.2/Debian-19) with ESMTPS id 05LHoiS3305894 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 02:50:45 +0900 Received: from devron.myhome.or.jp (foobar@localhost [127.0.0.1]) by devron.myhome.or.jp (8.15.2/8.15.2/Debian-19) with ESMTPS id 05LHoiV51124458 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 02:50:44 +0900 Received: (from hirofumi@localhost) by devron.myhome.or.jp (8.15.2/8.15.2/Submit) id 05LHoiZ21124457; Mon, 22 Jun 2020 02:50:44 +0900 From: OGAWA Hirofumi To: trix@redhat.com Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] fat: add a check to fat_add_new_entries References: <20200616162922.26168-1-trix@redhat.com> Date: Mon, 22 Jun 2020 02:50:44 +0900 In-Reply-To: <20200616162922.26168-1-trix@redhat.com> (trix@redhat.com's message of "Tue, 16 Jun 2020 09:29:22 -0700") Message-ID: <871rm8b957.fsf@mail.parknet.co.jp> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org trix@redhat.com writes: > start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]); > last_blknr = start_blknr + sbi->sec_per_clus; > + > + /* overflow */ > + if (unlikely(last_blknr <= start_blknr)) { > + err = -ENOMEM; > + goto error_nomem; > + } > + The cluster is 28bits and sec_per_clus is 8bits, so this should never overflow actually. Is there no way to tell it to clang? Thanks. -- OGAWA Hirofumi