Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbdFAPzF (ORCPT ); Thu, 1 Jun 2017 11:55:05 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33847 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752273AbdFAPpS (ORCPT ); Thu, 1 Jun 2017 11:45:18 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Thomas Hellstrom" , "Li Qiang" , "Li Qiang" Date: Thu, 01 Jun 2017 16:43:16 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 189/212] drm/vmwgfx: fix integer overflow in vmw_surface_define_ioctl() In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1306 Lines: 37 3.16.44-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Li Qiang commit e7e11f99564222d82f0ce84bd521e57d78a6b678 upstream. In vmw_surface_define_ioctl(), the 'num_sizes' is the sum of the 'req->mip_levels' array. This array can be assigned any value from the user space. As both the 'num_sizes' and the array is uint32_t, it is easy to make 'num_sizes' overflow. The later 'mip_levels' is used as the loop count. This can lead an oob write. Add the check of 'req->mip_levels' to avoid this. Signed-off-by: Li Qiang Reviewed-by: Thomas Hellstrom Signed-off-by: Ben Hutchings --- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -711,8 +711,11 @@ int vmw_surface_define_ioctl(struct drm_ 128; num_sizes = 0; - for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i) + for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i) { + if (req->mip_levels[i] > DRM_VMW_MAX_MIP_LEVELS) + return -EINVAL; num_sizes += req->mip_levels[i]; + } if (num_sizes > DRM_VMW_MAX_SURFACE_FACES * DRM_VMW_MAX_MIP_LEVELS || num_sizes == 0)