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=-3.8 required=3.0 tests=BAYES_00, 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 D60C1C433DB for ; Fri, 12 Feb 2021 12:50:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0F5464DA5 for ; Fri, 12 Feb 2021 12:50:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231637AbhBLMuT (ORCPT ); Fri, 12 Feb 2021 07:50:19 -0500 Received: from mx2.suse.de ([195.135.220.15]:36612 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231753AbhBLMtD (ORCPT ); Fri, 12 Feb 2021 07:49:03 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 348E8AC90; Fri, 12 Feb 2021 12:48:22 +0000 (UTC) Message-ID: Subject: Re: [PATCH] spi: Skip zero-length transfers in spi_transfer_one_message() From: Nicolas Saenz Julienne To: Mark Brown Cc: Robin Murphy , Phil Elwell , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 12 Feb 2021 13:48:21 +0100 In-Reply-To: <20210212123118.GB6057@sirena.org.uk> References: <20210211180820.25757-1-nsaenzjulienne@suse.de> <20210212123118.GB6057@sirena.org.uk> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-v8DGUj7fz+Xkq1UEyNyZ" User-Agent: Evolution 3.38.3 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org --=-v8DGUj7fz+Xkq1UEyNyZ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2021-02-12 at 12:31 +0000, Mark Brown wrote: > On Thu, Feb 11, 2021 at 07:08:20PM +0100, Nicolas Saenz Julienne wrote: >=20 > > - if (xfer->tx_buf || xfer->rx_buf) { > > + if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) { >=20 > I think the issue here is more that some users were passing in buffers > with zero length transfers, the above check was already intended to > catch this case but was working on the assumption that if there was > nothing to transfer then no buffer would be provided. Fair enough, maybe it makes sense to move the check into __spi_validate() a= nd propagate an error upwards? Regads, Nicolas --=-v8DGUj7fz+Xkq1UEyNyZ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAmAmeRUACgkQlfZmHno8 x/7SsQf/TdB8vXIJOKUbyFOgMkt+2pL2NOhrR7/gOHjvswb5nPNd6x4hOAl1tPiM 8As/5uPnXbPvxhmsMzsXKjwcylJDD5z00lFCXNZNzmxOBGcBnEtfwDD9/9nTpke6 T5EsTsbMAU+nLbzlmX0pR6z0FGpzQkToxop0X+mp2IX8Hdxt9FwepKB3MdnC/Oq9 Af4G9mp0pd8tjEHmjckZLfAymQ4mJ1HW/xwSk6bnv1mG34UysJYWIOBfsx/IQM4F OSTjB+D/2yDcA6eS2MceKh9qV0CJA5UPEW3Z2zVfw9tq/R8/8iuzsjcoMPWY2bXL xW8iaDHqlzwPJkY6WfkQdbLNnQuR3Q== =2avD -----END PGP SIGNATURE----- --=-v8DGUj7fz+Xkq1UEyNyZ--