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=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 5FD6CC43387 for ; Wed, 26 Dec 2018 23:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24E5020811 for ; Wed, 26 Dec 2018 23:23:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545866580; bh=zqoV0dGA/2+AvojitoHgc0Sr7F4hCKNl6cKLJn6qVGY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=M2lmcDRvQdBW3zCCGMROtWy3Rg/gIimDBI/EDN34z5teHeEthc5i5FC22G2DcWwiz hnqJQtGNVm4uXxP9JqhGjt5tf1poKUKWOxmUHdofrJMMzLMuOTFK4U1VtNxwvGbOE4 Nh+sVzPpqDVAlwZtYdmTSbVrJv90z3CcTy6SwJtI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729769AbeLZXW7 (ORCPT ); Wed, 26 Dec 2018 18:22:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:43980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728533AbeLZXWS (ORCPT ); Wed, 26 Dec 2018 18:22:18 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D21AF218E2; Wed, 26 Dec 2018 23:22:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545866537; bh=zqoV0dGA/2+AvojitoHgc0Sr7F4hCKNl6cKLJn6qVGY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NM5zLdnYWLLraeWBHjd5Shf2QYjl34/dA4B/7knZzLVzsNv4KWP1V5TX9NyHnj+VZ euSZdRawiHGlEzrGQbHe4ulYZ5JPm5bnS0A721ViPJLJNDp5BN7Pk7D+QJvoGtCQZw zuQDzcZfFHfNcEDoU2PA5YlT5dyNHB2e0Sxg/XhU= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Colin Ian King , Thomas Gleixner , security@kernel.org, Sasha Levin Subject: [PATCH AUTOSEL 3.18 08/12] x86/mtrr: Don't copy uninitialized gentry fields back to userspace Date: Wed, 26 Dec 2018 17:57:36 -0500 Message-Id: <20181226225741.151608-8-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181226225741.151608-1-sashal@kernel.org> References: <20181226225741.151608-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King [ Upstream commit 32043fa065b51e0b1433e48d118821c71b5cd65d ] 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: Sasha Levin --- arch/x86/kernel/cpu/mtrr/if.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c index a041e094b8b9..5598de02d2b4 100644 --- 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 int cmd, unsigned long __arg) 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: -- 2.19.1