From patchwork Wed Jul 4 09:42:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 10506347 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8D1EE603D7 for ; Wed, 4 Jul 2018 09:43:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7050B28CA4 for ; Wed, 4 Jul 2018 09:43:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 647A228DA7; Wed, 4 Jul 2018 09:43:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 257D428CA4 for ; Wed, 4 Jul 2018 09:43:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9711C6EB44; Wed, 4 Jul 2018 09:43:03 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from userp2130.oracle.com (userp2130.oracle.com [156.151.31.86]) by gabe.freedesktop.org (Postfix) with ESMTPS id BADB76EB44 for ; Wed, 4 Jul 2018 09:43:02 +0000 (UTC) Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w649e8ZK038046; Wed, 4 Jul 2018 09:43:01 GMT Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2130.oracle.com with ESMTP id 2k0dnjj4yk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 04 Jul 2018 09:43:01 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w649h0Rp011441 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 4 Jul 2018 09:43:00 GMT Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w649h09o027632; Wed, 4 Jul 2018 09:43:00 GMT Received: from kili.mountain (/197.157.34.168) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 04 Jul 2018 02:42:59 -0700 Date: Wed, 4 Jul 2018 12:42:50 +0300 From: Dan Carpenter To: David Airlie , Gerd Hoffmann Subject: [PATCH] drm/virtio: fix bounds check in virtio_gpu_cmd_get_capset() Message-ID: <20180704094250.m7sgvvzg3dhcvv3h@kili.mountain> MIME-Version: 1.0 Content-Disposition: inline X-Mailer: git-send-email haha only kidding User-Agent: NeoMutt/20170113 (1.7.2) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8943 signatures=668704 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807040115 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kernel-janitors@vger.kernel.org, Gerd Hoffmann , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP This doesn't affect runtime because in the current code "idx" is always valid. First, we read from "vgdev->capsets[idx].max_size" before checking whether "idx" is within bounds. And secondly the bounds check is off by one so we could end up reading one element beyond the end of the vgdev->capsets[] array. Fixes: 62fb7a5e1096 ("virtio-gpu: add 3d/virgl support") Signed-off-by: Dan Carpenter diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 020070d483d3..4735bd1c7321 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -648,11 +648,11 @@ int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev, { struct virtio_gpu_get_capset *cmd_p; struct virtio_gpu_vbuffer *vbuf; - int max_size = vgdev->capsets[idx].max_size; + int max_size; struct virtio_gpu_drv_cap_cache *cache_ent; void *resp_buf; - if (idx > vgdev->num_capsets) + if (idx >= vgdev->num_capsets) return -EINVAL; if (version > vgdev->capsets[idx].max_version) @@ -662,6 +662,7 @@ int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev, if (!cache_ent) return -ENOMEM; + max_size = vgdev->capsets[idx].max_size; cache_ent->caps_cache = kmalloc(max_size, GFP_KERNEL); if (!cache_ent->caps_cache) { kfree(cache_ent);