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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 8F8A2CA9EA1 for ; Fri, 18 Oct 2019 10:15:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 659E1222C3 for ; Fri, 18 Oct 2019 10:15:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2442492AbfJRKP2 (ORCPT ); Fri, 18 Oct 2019 06:15:28 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:53440 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389149AbfJRKP2 (ORCPT ); Fri, 18 Oct 2019 06:15:28 -0400 Received: from 79.184.255.51.ipv4.supernova.orange.pl (79.184.255.51) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.292) id 07025921cfe5987f; Fri, 18 Oct 2019 12:15:26 +0200 From: "Rafael J. Wysocki" To: Colin King Cc: Jaroslav Kysela , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PNP: fix unintended sign extension on left shifts Date: Fri, 18 Oct 2019 12:15:26 +0200 Message-ID: <7928372.mU7jdBj7dM@kreacher> In-Reply-To: <20191014131608.31335-1-colin.king@canonical.com> References: <20191014131608.31335-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, October 14, 2019 3:16:08 PM CEST Colin King wrote: > From: Colin Ian King > > Shifting a u8 left will cause the value to be promoted to an integer. If > the top bit of the u8 is set then the following conversion to a 64 bit > resource_size_t will sign extend the value causing the upper 32 bits > to be set in the result. > > Fix this by casting the u8 value to a resource_size_t before the shift. > Original commit is pre-git history. > > Signed-off-by: Colin Ian King > --- > drivers/pnp/isapnp/core.c | 18 ++++++++++++------ > 1 file changed, 12 insertions(+), 6 deletions(-) > > diff --git a/drivers/pnp/isapnp/core.c b/drivers/pnp/isapnp/core.c > index 179b737280e1..c947b1673041 100644 > --- a/drivers/pnp/isapnp/core.c > +++ b/drivers/pnp/isapnp/core.c > @@ -511,10 +511,14 @@ static void __init isapnp_parse_mem32_resource(struct pnp_dev *dev, > unsigned char flags; > > isapnp_peek(tmp, size); > - min = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1]; > - max = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5]; > - align = (tmp[12] << 24) | (tmp[11] << 16) | (tmp[10] << 8) | tmp[9]; > - len = (tmp[16] << 24) | (tmp[15] << 16) | (tmp[14] << 8) | tmp[13]; > + min = ((resource_size_t)tmp[4] << 24) | (tmp[3] << 16) | > + (tmp[2] << 8) | tmp[1]; > + max = ((resource_size_t)tmp[8] << 24) | (tmp[7] << 16) | > + (tmp[6] << 8) | tmp[5]; > + align = ((resource_size_t)tmp[12] << 24) | (tmp[11] << 16) | > + (tmp[10] << 8) | tmp[9]; > + len = ((resource_size_t)tmp[16] << 24) | (tmp[15] << 16) | > + (tmp[14] << 8) | tmp[13]; > flags = tmp[0]; > pnp_register_mem_resource(dev, option_flags, > min, max, align, len, flags); > @@ -532,8 +536,10 @@ static void __init isapnp_parse_fixed_mem32_resource(struct pnp_dev *dev, > unsigned char flags; > > isapnp_peek(tmp, size); > - base = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1]; > - len = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5]; > + base = ((resource_size_t)tmp[4] << 24) | (tmp[3] << 16) | > + (tmp[2] << 8) | tmp[1]; > + len = ((resource_size_t)tmp[8] << 24) | (tmp[7] << 16) | > + (tmp[6] << 8) | tmp[5]; > flags = tmp[0]; > pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags); > } > Can you please respin this with a CC to linux-acpi?