From patchwork Wed Jan 25 07:07:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerd Hoffmann X-Patchwork-Id: 9536485 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 3C1156042B for ; Wed, 25 Jan 2017 07:07:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 528F0204BF for ; Wed, 25 Jan 2017 07:07:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 43D0626E69; Wed, 25 Jan 2017 07:07:53 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 762E0204BF for ; Wed, 25 Jan 2017 07:07:51 +0000 (UTC) Received: from localhost ([::1]:57744 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cWHgK-0002T0-WF for patchwork-qemu-devel@patchwork.kernel.org; Wed, 25 Jan 2017 02:07:49 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39022) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cWHft-0002Su-91 for qemu-devel@nongnu.org; Wed, 25 Jan 2017 02:07:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cWHfp-0000im-TH for qemu-devel@nongnu.org; Wed, 25 Jan 2017 02:07:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56640) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cWHfp-0000if-NW; Wed, 25 Jan 2017 02:07:17 -0500 Received: from smtp.corp.redhat.com (int-mx16.intmail.prod.int.phx2.redhat.com [10.5.11.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0CA543A7689; Wed, 25 Jan 2017 07:07:16 +0000 (UTC) Received: from nilsson.home.kraxel.org (ovpn-116-45.ams2.redhat.com [10.36.116.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id 63B451CD1D1; Wed, 25 Jan 2017 07:07:13 +0000 (UTC) Received: by nilsson.home.kraxel.org (Postfix, from userid 500) id 4C51A80734; Wed, 25 Jan 2017 08:07:11 +0100 (CET) From: Gerd Hoffmann To: qemu-devel@nongnu.org Date: Wed, 25 Jan 2017 08:07:05 +0100 Message-Id: <1485328025-3783-1-git-send-email-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.74 on 10.5.11.28 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 25 Jan 2017 07:07:16 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] cirrus: fix oob access issue (CVE-2017-TODO) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wolfgang Bumiller , Li Qiang , qemu-stable@nongnu.org, P J P , Gerd Hoffmann , Paolo Bonzini , Laszlo Ersek Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Li Qiang When doing bitblt copy in backward mode, we should minus the blt width first just like the adding in the forward mode. This can avoid the oob access of the front of vga's vram. Signed-off-by: Li Qiang Message-id: 5887254f.863a240a.2c122.5500@mx.google.com { kraxel: with backward blits (negative pitch) addr is the topmost address, so check it as-is against vram size ] Cc: qemu-stable@nongnu.org Cc: P J P Cc: Laszlo Ersek Cc: Paolo Bonzini Cc: Wolfgang Bumiller Fixes: d3532a0db02296e687711b8cdc7791924efccea0 (CVE-2014-8106) Signed-off-by: Gerd Hoffmann --- hw/display/cirrus_vga.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index 379910d..b8c29a6 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -277,10 +277,9 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s, } if (pitch < 0) { int64_t min = addr - + ((int64_t)s->cirrus_blt_height-1) * pitch; - int32_t max = addr - + s->cirrus_blt_width; - if (min < 0 || max > s->vga.vram_size) { + + ((int64_t)s->cirrus_blt_height - 1) * pitch + - s->cirrus_blt_width; + if (min < 0 || addr > s->vga.vram_size) { return true; } } else {