From patchwork Fri Jun 3 07:34:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Gerd Hoffmann X-Patchwork-Id: 629641 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rLbZj5dFmz9t84 for ; Fri, 3 Jun 2016 17:39:25 +1000 (AEST) Received: from localhost ([::1]:52946 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8jhT-0002oD-O3 for incoming@patchwork.ozlabs.org; Fri, 03 Jun 2016 03:39:23 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37705) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8jdB-0007Vq-AR for qemu-devel@nongnu.org; Fri, 03 Jun 2016 03:34:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b8jd3-00004w-N9 for qemu-devel@nongnu.org; Fri, 03 Jun 2016 03:34:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53353) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8jd3-0008WO-IM for qemu-devel@nongnu.org; Fri, 03 Jun 2016 03:34:49 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1844B80096 for ; Fri, 3 Jun 2016 07:34:49 +0000 (UTC) Received: from nilsson.home.kraxel.org (ovpn-116-36.ams2.redhat.com [10.36.116.36]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u537YmVS027289; Fri, 3 Jun 2016 03:34:48 -0400 Received: by nilsson.home.kraxel.org (Postfix, from userid 500) id 4584C81AD3; Fri, 3 Jun 2016 09:34:46 +0200 (CEST) From: Gerd Hoffmann To: qemu-devel@nongnu.org Date: Fri, 3 Jun 2016 09:34:42 +0200 Message-Id: <1464939283-32184-6-git-send-email-kraxel@redhat.com> In-Reply-To: <1464939283-32184-1-git-send-email-kraxel@redhat.com> References: <1464939283-32184-1-git-send-email-kraxel@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 03 Jun 2016 07:34:49 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 5/6] vmsvga: don't process more than 1024 fifo commands at once 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: Gerd Hoffmann , P J P Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" vmsvga_fifo_run is called in regular intervals (on each display update) and will resume where it left off. So we can simply exit the loop, without having to worry about how processing will continue. Fixes: CVE-2016-4453 Cc: P J P Reported-by: 李强 Signed-off-by: Gerd Hoffmann Message-id: 1464592161-18348-5-git-send-email-kraxel@redhat.com --- hw/display/vmware_vga.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/display/vmware_vga.c b/hw/display/vmware_vga.c index de2567b..e51a05e 100644 --- a/hw/display/vmware_vga.c +++ b/hw/display/vmware_vga.c @@ -597,13 +597,13 @@ static inline uint32_t vmsvga_fifo_read(struct vmsvga_state_s *s) static void vmsvga_fifo_run(struct vmsvga_state_s *s) { uint32_t cmd, colour; - int args, len; + int args, len, maxloop = 1024; int x, y, dx, dy, width, height; struct vmsvga_cursor_definition_s cursor; uint32_t cmd_start; len = vmsvga_fifo_length(s); - while (len > 0) { + while (len > 0 && --maxloop > 0) { /* May need to go back to the start of the command if incomplete */ cmd_start = s->fifo_stop;