From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755012AbcBPLtl (ORCPT ); Tue, 16 Feb 2016 06:49:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45128 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750953AbcBPLtj (ORCPT ); Tue, 16 Feb 2016 06:49:39 -0500 From: Gerd Hoffmann To: David Airlie Cc: Gerd Hoffmann , stable@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, dri-devel@lists.freedesktop.org (open list:DRM DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] qxl: apply limit to relocs_num in qxl_process_single_command Date: Tue, 16 Feb 2016 12:49:23 +0100 Message-Id: <1455623363-9224-1-git-send-email-kraxel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Limit relocs_num to 65536. That limit is small enougth to avoid integer overflow on 32bit machines when calculating reloc_info size (as reported by Alan Cox), and is big enougth to not block normal usage (kmalloc would ENOMEM on requests larger than that anyway). Cc: stable@vger.kernel.org Cc: gnomes@lxorguk.ukuu.org.uk Signed-off-by: Gerd Hoffmann --- drivers/gpu/drm/qxl/qxl_ioctl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/qxl/qxl_ioctl.c b/drivers/gpu/drm/qxl/qxl_ioctl.c index 2ae8577..970cb83 100644 --- a/drivers/gpu/drm/qxl/qxl_ioctl.c +++ b/drivers/gpu/drm/qxl/qxl_ioctl.c @@ -168,6 +168,8 @@ static int qxl_process_single_command(struct qxl_device *qdev, cmd->command_size)) return -EFAULT; + if (cmd->relocs_num > 65536) + return -EINVAL; reloc_info = kmalloc(sizeof(struct qxl_reloc_info) * cmd->relocs_num, GFP_KERNEL); if (!reloc_info) return -ENOMEM; -- 1.8.3.1