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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 8D24EC43387 for ; Fri, 28 Dec 2018 12:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5105820675 for ; Fri, 28 Dec 2018 12:20:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545999638; bh=ayBqv0ZgtBntGG2i6LIqxRQxfLdjrd6iPSCNUv3lQD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Y4lIxeMGeBTYexP0v7aWZo81UeEHIyPdCvpwInMIgKuCcRPb+FXRNofL0I0SluSCV 2jUAje0RmSBxPnqDcDDyxcICKp+x8tYTiIYeOqIzIAigIMoiwWHeRpRIDM0nNTo698 /5tLYHcDu6+5HjLkNFwwaeYpR1RgpcIvfRf91v4o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732694AbeL1MQ0 (ORCPT ); Fri, 28 Dec 2018 07:16:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:35422 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732671AbeL1MQV (ORCPT ); Fri, 28 Dec 2018 07:16:21 -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 7DFA72184B; Fri, 28 Dec 2018 12:16:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545999381; bh=ayBqv0ZgtBntGG2i6LIqxRQxfLdjrd6iPSCNUv3lQD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hLkh3d7TPif1RUDp19tzw4nBbsAXfZkGCqa8Qiw3dSsNXhaBz3pphbFEDP6XG1OHb vUz8sonlFqEc3w1cEFt2ctI5WXrD6935TPLZcNd/a/Iqno2sQ8a0VQrc/j4Sn/TAST Ogse07S4jIKh//eZp6gv2tb+MEXkTPExaRlOYpzI= 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 4.14 27/36] x86/mtrr: Dont copy uninitialized gentry fields back to userspace Date: Fri, 28 Dec 2018 12:52:43 +0100 Message-Id: <20181228113128.368524192@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20181228113126.526729877@linuxfoundation.org> References: <20181228113126.526729877@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 4.14-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: