From patchwork Wed May 16 14:00:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 10404025 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 BEA9A601D2 for ; Wed, 16 May 2018 14:01:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A867F28B3F for ; Wed, 16 May 2018 14:01:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9CB4328A20; Wed, 16 May 2018 14:01:05 +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=-5.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, 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 25E9C28A20 for ; Wed, 16 May 2018 14:00:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B50CB6E41E; Wed, 16 May 2018 14:00:47 +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 D83C56E41E for ; Wed, 16 May 2018 14:00:46 +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 w4GE0eck175508; Wed, 16 May 2018 14:00:40 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 : in-reply-to; s=corp-2017-10-26; bh=2Aess8t7jsd00Xj5qaNT9HYFRXgz3MyKv9BNqwR8JkA=; b=L4XbbdSU24tdvptSjqowfR/CcQ2YjcYJAoBJD3sXmlopT0YaXiqXpLYrjDetl/Prb3UA c8+Q89tYZEqwo6dX9NN8s+Y6f1she5jgnMdOJjjm/fPZAoimxiatUXEtKmo+xfm665bE UBHg0iywJJdDLJQ1KpX/4nf3ll+cb535ffVTcm8+T95LlGOnM0miGzMfxf5h+I3woHaI i4p//Ta0w1NqQGXpiJFLD9ARydqmyewA20s1SkMgtFTvBjZMuEO5kIzbB/ZP1zzu8LL7 eKwUPvmBP/iVBAxqjVzcUozYR/g5MR56vnQua6vLcCsqgXxZhnLJwp5KU1CKTbiaPela UQ== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2130.oracle.com with ESMTP id 2hx29wd03w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 16 May 2018 14:00:40 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w4GE0a0A025534 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 16 May 2018 14:00:37 GMT Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w4GE0ZBE030714; Wed, 16 May 2018 14:00:35 GMT Received: from mwanda (/197.254.35.146) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 16 May 2018 07:00:34 -0700 Date: Wed, 16 May 2018 17:00:26 +0300 From: Dan Carpenter To: Gustavo Padovan Subject: [PATCH v2] drm/dumb-buffers: Integer overflow in drm_mode_create_ioctl() Message-ID: <20180516140026.GA19340@mwanda> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <152585393757.3513.738158010667924495@mail.alporthouse.com> X-Mailer: git-send-email haha only kidding User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8894 signatures=668698 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=8.0.1-1711220000 definitions=main-1805160142 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: David Airlie , kernel-janitors@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP There is a comment here which says that DIV_ROUND_UP() and that's where the problem comes from. Say you pick: args->bpp = UINT_MAX - 7; args->width = 4; args->height = 1; The integer overflow in DIV_ROUND_UP() means "cpp" is UINT_MAX / 8 and because of how we picked args->width that means cpp < UINT_MAX / 4. I've fixed it by preventing the integer overflow in DIV_ROUND_UP(). I removed the check for !cpp because it's not possible after this change. I also changed all the 0xffffffffU references to U32_MAX. Signed-off-by: Dan Carpenter Reviewed-by: Chris Wilson --- v2: additional cleanups diff --git a/drivers/gpu/drm/drm_dumb_buffers.c b/drivers/gpu/drm/drm_dumb_buffers.c index 39ac15ce4702..9e2ae02f31e0 100644 --- a/drivers/gpu/drm/drm_dumb_buffers.c +++ b/drivers/gpu/drm/drm_dumb_buffers.c @@ -65,12 +65,13 @@ int drm_mode_create_dumb_ioctl(struct drm_device *dev, return -EINVAL; /* overflow checks for 32bit size calculations */ - /* NOTE: DIV_ROUND_UP() can overflow */ + if (args->bpp > U32_MAX - 8) + return -EINVAL; cpp = DIV_ROUND_UP(args->bpp, 8); - if (!cpp || cpp > 0xffffffffU / args->width) + if (cpp > U32_MAX / args->width) return -EINVAL; stride = cpp * args->width; - if (args->height > 0xffffffffU / stride) + if (args->height > U32_MAX / stride) return -EINVAL; /* test for wrap-around */