Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754189AbaFEEcE (ORCPT ); Thu, 5 Jun 2014 00:32:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44456 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753478AbaFEEWJ (ORCPT ); Thu, 5 Jun 2014 00:22:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Roskin , Chris Wilson , Dave Airlie , Ben Hutchings , Weng Meiling , dri-devel@lists.freedesktop.org Subject: [PATCH 3.4 184/214] drm: Pad drm_mode_get_connector to 64-bit boundary Date: Wed, 4 Jun 2014 21:19:07 -0700 Message-Id: <20140605041704.189869660@linuxfoundation.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <20140605041639.638675216@linuxfoundation.org> References: <20140605041639.638675216@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit bc5bd37ce48c66e9192ad2e7231e9678880f6f8e upstream. Pavel Roskin reported that DRM_IOCTL_MODE_GETCONNECTOR was overwritting the 4 bytes beyond the end of its structure with a 32-bit userspace running on a 64-bit kernel. This is due to the padding gcc inserts as the drm_mode_get_connector struct includes a u64 and its size is not a natural multiple of u64s. 64-bit kernel: sizeof(drm_mode_get_connector)=80, alignof=8 sizeof(drm_mode_get_encoder)=20, alignof=4 sizeof(drm_mode_modeinfo)=68, alignof=4 32-bit userspace: sizeof(drm_mode_get_connector)=76, alignof=4 sizeof(drm_mode_get_encoder)=20, alignof=4 sizeof(drm_mode_modeinfo)=68, alignof=4 Fortuituously we can insert explicit padding to the tail of our structures without breaking ABI. Reported-by: Pavel Roskin Signed-off-by: Chris Wilson Cc: Dave Airlie Cc: dri-devel@lists.freedesktop.org Signed-off-by: Dave Airlie [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings Cc: Weng Meiling Signed-off-by: Greg Kroah-Hartman --- include/drm/drm_mode.h | 2 ++ 1 file changed, 2 insertions(+) --- a/include/drm/drm_mode.h +++ b/include/drm/drm_mode.h @@ -223,6 +223,8 @@ struct drm_mode_get_connector { __u32 connection; __u32 mm_width, mm_height; /**< HxW in millimeters */ __u32 subpixel; + + __u32 pad; }; #define DRM_MODE_PROP_PENDING (1<<0) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/