From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751319AbdEDJFu (ORCPT ); Thu, 4 May 2017 05:05:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:59677 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751539AbdEDJEz (ORCPT ); Thu, 4 May 2017 05:04:55 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Murray McAllister , Jiri Slaby Subject: [PATCH 3.12 02/86] drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() Date: Thu, 4 May 2017 11:03:27 +0200 Message-Id: X-Mailer: git-send-email 2.12.2 In-Reply-To: <13a6a971c9165237531c2870da03084a6becc905.1493888632.git.jslaby@suse.cz> References: <13a6a971c9165237531c2870da03084a6becc905.1493888632.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Murray McAllister 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 63774069d9527a1aeaa4aa20e929ef5e8e9ecc38 upstream. In vmw_get_cap_3d_ioctl(), a user can supply 0 for a size that is used in vzalloc(). This eventually calls dump_stack() (in warn_alloc()), which can leak useful addresses to dmesg. Add check to avoid a size of 0. Signed-off-by: Murray McAllister Reviewed-by: Sinclair Yeh Signed-off-by: Jiri Slaby --- drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c index c509d40c4897..f435b6c187f0 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c @@ -90,7 +90,7 @@ int vmw_get_cap_3d_ioctl(struct drm_device *dev, void *data, void *bounce; int ret; - if (unlikely(arg->pad64 != 0)) { + if (unlikely(arg->pad64 != 0 || arg->max_size == 0)) { DRM_ERROR("Illegal GET_3D_CAP argument.\n"); return -EINVAL; } -- 2.12.2