From patchwork Fri Oct 23 11:29:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 11852801 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=-9.8 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 autolearn=unavailable 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 01CF8C55178 for ; Fri, 23 Oct 2020 11:30:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B324024655 for ; Fri, 23 Oct 2020 11:30:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="TNJkekHO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S463021AbgJWLaI (ORCPT ); Fri, 23 Oct 2020 07:30:08 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:45982 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S462965AbgJWLaH (ORCPT ); Fri, 23 Oct 2020 07:30:07 -0400 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 09NBOsSl131525; Fri, 23 Oct 2020 11:29:55 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2020-01-29; bh=9kf8P27vyBYNLjGzKO/Jue2/64fmWTjPZNf2k5fKmhc=; b=TNJkekHOIZJkGE8PQeteOXT9/QZzO75g69x/3tecYzA5a26/GsCvAPMCGoSI1T7stUAe vn/emSRZwmIOAwuBlm/URzTM3IXdgCcdwnlQqS3PKmhL6HYg3ni8EODNGSI/4U3EYmZj URqL0R8k+Nn2Swmnq0EPyHB6rvH7OkNyK60f7NwoJBLerlqS5WqGnmunRnDk3UHZeluR R2Pz1AvqxfRJbvwH7UjxO4XTJVsUfxMi+k3Vs9zKCu3AXoGvx1WlUJuLnJ+OfRJwAw08 Mz05agl56NwfZLSdUC4xqFYCYi5Osw1gcTnCnaMqOsNpp76Lo23DbDzZnPFBlBYBu73x pA== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 349jrq2s4q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 23 Oct 2020 11:29:55 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 09NBPl33123798; Fri, 23 Oct 2020 11:29:54 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 348ah1w9em-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 23 Oct 2020 11:29:54 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 09NBTsiL031037; Fri, 23 Oct 2020 11:29:54 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 23 Oct 2020 04:29:53 -0700 Date: Fri, 23 Oct 2020 14:29:47 +0300 From: Dan Carpenter To: Diana Craciun Cc: Alex Williamson , Cornelia Huck , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH 2/2] vfio/fsl-mc: prevent underflow in vfio_fsl_mc_mmap() Message-ID: <20201023112947.GF282278@mwanda> MIME-Version: 1.0 Content-Disposition: inline X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9782 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 phishscore=0 malwarescore=0 spamscore=0 suspectscore=0 bulkscore=0 mlxlogscore=981 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010230081 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9782 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 lowpriorityscore=0 priorityscore=1501 impostorscore=0 adultscore=0 bulkscore=0 malwarescore=0 mlxlogscore=993 mlxscore=0 spamscore=0 suspectscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010230081 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org My static analsysis tool complains that the "index" can be negative. There are some checks in do_mmap() which try to prevent underflows but I don't know if they are sufficient for this situation. Either way, making "index" unsigned is harmless so let's do it just to be safe. Fixes: 67247289688d ("vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions") Signed-off-by: Dan Carpenter Acked-by: Diana Craciun --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c index 21f22e3da11f..f27e25112c40 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -472,7 +472,7 @@ static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma) { struct vfio_fsl_mc_device *vdev = device_data; struct fsl_mc_device *mc_dev = vdev->mc_dev; - int index; + unsigned int index; index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT);