Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751123AbdLIGiG (ORCPT ); Sat, 9 Dec 2017 01:38:06 -0500 Received: from gateway33.websitewelcome.com ([192.185.146.130]:33299 "EHLO gateway33.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbdLIGiE (ORCPT ); Sat, 9 Dec 2017 01:38:04 -0500 Date: Sat, 9 Dec 2017 00:37:59 -0600 From: "Gustavo A. R. Silva" To: Zhenyu Wang , Zhi Wang , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie Cc: intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] drm/i915/gvt/fb_decoder: Fix out-of-bounds read Message-ID: <20171209063759.GA8672@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.155.98.198 X-Source-L: No X-Exim-ID: 1eNYlt-0033EH-Ar X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.155.98.198]:40604 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 10 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1459 Lines: 37 In case function skl_format_to_drm returns -EINVAL, fmt turns into a huge number as fmt is of type u32, hence there is an out-of-bounds read when using fmt as an index for array skl_pixel_formats at line 225: plane->bpp = skl_pixel_formats[fmt].bpp; Fix this by comparing the value returned by function skl_format_to_drm against the size of array skl_pixel_formats, so in case it is greater than or equal to the number of items contained in skl_pixel_formats, print an error message and return -EINVAL. Addresses-Coverity-ID: 1462495 Addresses-Coverity-ID: 1462502 ("Out-of-bounds read") Fixes: 9f31d1063b43 ("drm/i915/gvt: Add framebuffer decoder support") Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/i915/gvt/fb_decoder.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/i915/gvt/fb_decoder.c b/drivers/gpu/drm/i915/gvt/fb_decoder.c index 72f4217..aed578b 100644 --- a/drivers/gpu/drm/i915/gvt/fb_decoder.c +++ b/drivers/gpu/drm/i915/gvt/fb_decoder.c @@ -222,6 +222,12 @@ int intel_vgpu_decode_primary_plane(struct intel_vgpu *vgpu, val & PLANE_CTL_ORDER_RGBX, val & PLANE_CTL_ALPHA_MASK, val & PLANE_CTL_YUV422_ORDER_MASK); + + if (fmt >= ARRAY_SIZE(skl_pixel_formats)) { + gvt_vgpu_err("Out-of-bounds pixel format index\n"); + return -EINVAL; + } + plane->bpp = skl_pixel_formats[fmt].bpp; plane->drm_format = skl_pixel_formats[fmt].drm_format; } else { -- 2.7.4