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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1E99C77B6E for ; Wed, 12 Apr 2023 13:05:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pma8z-0003ju-Sr; Wed, 12 Apr 2023 09:04:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pma8x-0003if-7g for qemu-devel@nongnu.org; Wed, 12 Apr 2023 09:04:11 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pma8u-00057p-4Y for qemu-devel@nongnu.org; Wed, 12 Apr 2023 09:04:10 -0400 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4PxN9T3m2wz6H84D; Wed, 12 Apr 2023 21:00:29 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Wed, 12 Apr 2023 14:02:51 +0100 Date: Wed, 12 Apr 2023 14:02:50 +0100 To: Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= CC: Hao Zeng , , , Subject: Re: [PATCH v2 2/2] cxl-cdat:Fix the check on the return value of fread() Message-ID: <20230412140250.00000d4a@Huawei.com> In-Reply-To: <07ab950e-7ee4-2476-9032-4638fe6eed1f@linaro.org> References: <20230412071633.2660412-1-zenghao@kylinos.cn> <20230412071633.2660412-3-zenghao@kylinos.cn> <07ab950e-7ee4-2476-9032-4638fe6eed1f@linaro.org> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Jonathan Cameron From: Jonathan Cameron via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 12 Apr 2023 12:02:47 +0200 Philippe Mathieu-Daud=E9 wrote: > On 12/4/23 09:16, Hao Zeng wrote: > > The bug in this code (CID 1507822) is that the > > check on the return value of fread() is wrong. fread() > > returns the number of items read or written, so > > checking for =3D=3D 0 only catches "no data read at all", > > not "only read half the data". > >=20 > > Signed-off-by: Zeng Hao > > Suggested-by: Peter Maydell > > --- > > hw/cxl/cxl-cdat.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > >=20 > > diff --git a/hw/cxl/cxl-cdat.c b/hw/cxl/cxl-cdat.c > > index ba7ed1aafd..130531a9cd 100644 > > --- a/hw/cxl/cxl-cdat.c > > +++ b/hw/cxl/cxl-cdat.c > > @@ -126,7 +126,7 @@ static void ct3_load_cdat(CDATObject *cdat, Error *= *errp) > > fseek(fp, 0, SEEK_SET); > > cdat->buf =3D g_malloc0(file_size); =20 >=20 > Pointless bzero in g_malloc0, however this code would be > simplified using g_file_get_contents(). Agreed - switching this whole thing to g_file_get_contents() will get rid of this code and be a lot simpler. Perhaps just jump directly to that and note the two bugs that existed in the code that is replaced? Jonathan =20 >=20 > > =20 > > - if (fread(cdat->buf, file_size, 1, fp) =3D=3D 0) { > > + if (fread(cdat->buf, file_size, 1, fp) !=3D file_size) { > > error_setg(errp, "CDAT: File read failed"); > > fclose(fp); > > return; =20 >=20