From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 290D2C43387 for ; Fri, 11 Jan 2019 14:26:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E471C2177B for ; Fri, 11 Jan 2019 14:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547216772; bh=Qhk/2P48zIr1OxkJBCIirYBQp+qXFzKeB2+b5eg655w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Pp5kAjNQMQ+gfpooCmefRylvifW6wzJ5PjcaDaqBzXdxMCdxDV38F6swyAYzQro5b ax0MNDRdD49IezYT/BKhebHwvz7xChchjug1+937p55nTWZa8v2HdE/FK5XmlSrSd3 aYphLjkBkSkr6fy4wNXpeuBZ/8h19TviztusV5RQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388286AbfAKO0L (ORCPT ); Fri, 11 Jan 2019 09:26:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:34684 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726503AbfAKOSN (ORCPT ); Fri, 11 Jan 2019 09:18:13 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 83C5421841; Fri, 11 Jan 2019 14:18:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547216293; bh=Qhk/2P48zIr1OxkJBCIirYBQp+qXFzKeB2+b5eg655w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZqgRUQM22Tj11K95JHvvYJ6NyMxXDGiIVO9Z0yRnvq26RubTbaDBpR1sc7zkXytNO 5qMbygZlcCfybc0Q3esX+kOVy2QCfmZXY8ZsW2PBH0PN+R0p3ujNwjv7Wmkpv8YhVK bSaYr7mJv+zcKpdiy5ugtTVtvvh/iuE0uW4aoUpQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Thomas Gleixner , Tyler Hicks , security@kernel.org Subject: [PATCH 4.4 12/88] x86/mtrr: Dont copy uninitialized gentry fields back to userspace Date: Fri, 11 Jan 2019 15:07:41 +0100 Message-Id: <20190111131048.027594430@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111131045.137499039@linuxfoundation.org> References: <20190111131045.137499039@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Colin Ian King commit 32043fa065b51e0b1433e48d118821c71b5cd65d upstream. Currently the copy_to_user of data in the gentry struct is copying uninitiaized data in field _pad from the stack to userspace. Fix this by explicitly memset'ing gentry to zero, this also will zero any compiler added padding fields that may be in struct (currently there are none). Detected by CoverityScan, CID#200783 ("Uninitialized scalar variable") Fixes: b263b31e8ad6 ("x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls") Signed-off-by: Colin Ian King Signed-off-by: Thomas Gleixner Reviewed-by: Tyler Hicks Cc: security@kernel.org Link: https://lkml.kernel.org/r/20181218172956.1440-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/mtrr/if.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/x86/kernel/cpu/mtrr/if.c +++ b/arch/x86/kernel/cpu/mtrr/if.c @@ -173,6 +173,8 @@ mtrr_ioctl(struct file *file, unsigned i struct mtrr_gentry gentry; void __user *arg = (void __user *) __arg; + memset(&gentry, 0, sizeof(gentry)); + switch (cmd) { case MTRRIOC_ADD_ENTRY: case MTRRIOC_SET_ENTRY: