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=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_SANE_1 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 86218C2D0A3 for ; Fri, 6 Nov 2020 08:04:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3111E2087E for ; Fri, 6 Nov 2020 08:04:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="CNrVNUJ3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbgKFIEr (ORCPT ); Fri, 6 Nov 2020 03:04:47 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:60808 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbgKFIEq (ORCPT ); Fri, 6 Nov 2020 03:04:46 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A683xbP066041; Fri, 6 Nov 2020 08:04:31 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=OQ/5L/oc4/wCEiOu/3QR8Botu+fEhl2YqoR8s63vgq4=; b=CNrVNUJ30cGBaOtmhh6Svsq0E66IlgCSnOP7mcFcG8v39OSujJAC/B17S1eOk7Fsr5Ql tTqVAldVfjyPNOwjsA/M7p8hrhtwMD3QIldcFo/TV3/XtqdOpSI01bZf3/yVJiIIiB85 NNhOvfLmrf60unt7H6y5XdUGSbtYxdAVFNfKgkSDWQzdK2zh5zgCN3Dnw/Uk/FiA5uWu RCZc+zb2uGJy0tjWeVqv+6knLMZFDkAWo3ru/aA9+MH87zSLp2Usv2/1b8AnUv+M19jO peMLpcRKiaC17yfSkwZDdoX7/wbAh7XVg0KjfkyEIWVZbwr2khGEN5z2NSqI2siijkLt jw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 34hhvcqqu7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 06 Nov 2020 08:04:31 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A67tqTY124113; Fri, 6 Nov 2020 08:04:30 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 34hvs23x2n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 06 Nov 2020 08:04:30 +0000 Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0A684SoJ007269; Fri, 6 Nov 2020 08:04:28 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 06 Nov 2020 00:04:27 -0800 Date: Fri, 6 Nov 2020 11:04:19 +0300 From: Dan Carpenter To: Bjorn Helgaas Cc: Colin King , Bjorn Helgaas , Christian =?iso-8859-1?Q?K=F6nig?= , Stephen Bates , Logan Gunthorpe , Alex Williamson , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] PCI: fix a potential uninitentional integer overflow issue Message-ID: <20201106080419.GC29398@kadam> References: <20201007123045.GS4282@kadam> <20201105222430.GA499522@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201105222430.GA499522@bjorn-Precision-5520> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9796 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 adultscore=0 mlxscore=0 malwarescore=0 mlxlogscore=999 suspectscore=0 spamscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011060056 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9796 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 impostorscore=0 malwarescore=0 priorityscore=1501 mlxlogscore=999 bulkscore=0 phishscore=0 adultscore=0 mlxscore=0 lowpriorityscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011060057 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 05, 2020 at 04:24:30PM -0600, Bjorn Helgaas wrote: > On Wed, Oct 07, 2020 at 03:33:45PM +0300, Dan Carpenter wrote: > > On Wed, Oct 07, 2020 at 12:46:15PM +0100, Colin King wrote: > > > From: Colin Ian King > > > > > > The shift of 1 by align_order is evaluated using 32 bit arithmetic > > > and the result is assigned to a resource_size_t type variable that > > > is a 64 bit unsigned integer on 64 bit platforms. Fix an overflow > > > before widening issue by using the BIT_ULL macro to perform the > > > shift. > > > > > > Addresses-Coverity: ("Uninitentional integer overflow") > > s/Uninitentional/Unintentional/ > Also in subject (please also capitalize subject) > > Doesn't Coverity also assign an ID number for this specific issue? > Can you include that as well, e.g., > > Addresses-Coverity-ID: 1226899 ("Unintentional integer overflow") > > > > Fixes: 07d8d7e57c28 ("PCI: Make specifying PCI devices in kernel parameters reusable") > > > Signed-off-by: Colin Ian King > > > --- > > > drivers/pci/pci.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index 6d4d5a2f923d..1a5844d7af35 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -6209,7 +6209,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev, > > > if (align_order == -1) > > > align = PAGE_SIZE; > > > else > > > - align = 1 << align_order; > > > + align = BIT_ULL(align_order); > > > > "align_order" comes from sscanf() so Smatch thinks it's not trusted. > > Anything above 63 is undefined behavior. There should be a bounds check > > on this but I don't know what the valid values of "align" are. > > The spec doesn't explicitly say what the size limit for 64-bit BARs > is, but it does say 32-bit BARs can support up to 2GB (2^31). So I > infer that 2^63 would be the limit for 64-bit BARs. > > What about something like the following? To me, BIT_ULL doesn't seem > like an advantage over "1ULL << ", but maybe there's a reason to use > it. The advantage of BIT_ULL() is that checkpatch and I think Coccinelle will suggest using it. It's only recently where a few people have complained (actually you're probably the second person) that BIT() is sort of a weird thing to use for size variables. regards, dan carpenter From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Fri, 06 Nov 2020 08:04:19 +0000 Subject: Re: [PATCH] PCI: fix a potential uninitentional integer overflow issue Message-Id: <20201106080419.GC29398@kadam> List-Id: References: <20201007123045.GS4282@kadam> <20201105222430.GA499522@bjorn-Precision-5520> In-Reply-To: <20201105222430.GA499522@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Bjorn Helgaas Cc: Colin King , Bjorn Helgaas , Christian =?iso-8859-1?Q?K=F6nig?= , Stephen Bates , Logan Gunthorpe , Alex Williamson , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org On Thu, Nov 05, 2020 at 04:24:30PM -0600, Bjorn Helgaas wrote: > On Wed, Oct 07, 2020 at 03:33:45PM +0300, Dan Carpenter wrote: > > On Wed, Oct 07, 2020 at 12:46:15PM +0100, Colin King wrote: > > > From: Colin Ian King > > > > > > The shift of 1 by align_order is evaluated using 32 bit arithmetic > > > and the result is assigned to a resource_size_t type variable that > > > is a 64 bit unsigned integer on 64 bit platforms. Fix an overflow > > > before widening issue by using the BIT_ULL macro to perform the > > > shift. > > > > > > Addresses-Coverity: ("Uninitentional integer overflow") > > s/Uninitentional/Unintentional/ > Also in subject (please also capitalize subject) > > Doesn't Coverity also assign an ID number for this specific issue? > Can you include that as well, e.g., > > Addresses-Coverity-ID: 1226899 ("Unintentional integer overflow") > > > > Fixes: 07d8d7e57c28 ("PCI: Make specifying PCI devices in kernel parameters reusable") > > > Signed-off-by: Colin Ian King > > > --- > > > drivers/pci/pci.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index 6d4d5a2f923d..1a5844d7af35 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -6209,7 +6209,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev, > > > if (align_order = -1) > > > align = PAGE_SIZE; > > > else > > > - align = 1 << align_order; > > > + align = BIT_ULL(align_order); > > > > "align_order" comes from sscanf() so Smatch thinks it's not trusted. > > Anything above 63 is undefined behavior. There should be a bounds check > > on this but I don't know what the valid values of "align" are. > > The spec doesn't explicitly say what the size limit for 64-bit BARs > is, but it does say 32-bit BARs can support up to 2GB (2^31). So I > infer that 2^63 would be the limit for 64-bit BARs. > > What about something like the following? To me, BIT_ULL doesn't seem > like an advantage over "1ULL << ", but maybe there's a reason to use > it. The advantage of BIT_ULL() is that checkpatch and I think Coccinelle will suggest using it. It's only recently where a few people have complained (actually you're probably the second person) that BIT() is sort of a weird thing to use for size variables. regards, dan carpenter