From patchwork Mon Mar 28 16:18:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 8679811 Return-Path: X-Original-To: patchwork-platform-driver-x86@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4061CC0553 for ; Mon, 28 Mar 2016 16:18:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5FDFF20225 for ; Mon, 28 Mar 2016 16:18:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11AC120220 for ; Mon, 28 Mar 2016 16:18:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754020AbcC1QSp (ORCPT ); Mon, 28 Mar 2016 12:18:45 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:51053 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754002AbcC1QSo (ORCPT ); Mon, 28 Mar 2016 12:18:44 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1akZsG-0005Xa-5e; Mon, 28 Mar 2016 16:18:40 +0000 From: Colin King To: Sujith Thomas , Darren Hart , platform-driver-x86@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] intel_menlow: set cdev after null device check to avoid null pointer dereference Date: Mon, 28 Mar 2016 17:18:39 +0100 Message-Id: <1459181919-13825-1-git-send-email-colin.king@canonical.com> X-Mailer: git-send-email 2.7.4 Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Colin Ian King intel_menlow_memory_remove sanity checks to see if device is null, however, this check is performed after we have already passed device into a call to acpi_driver_data. If device is null, then acpi_driver_data will produce a null pointer dereference on device. The correct action is to sanity check device, then assign cdev, then check if cdev is null. Signed-off-by: Colin Ian King --- drivers/platform/x86/intel_menlow.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/intel_menlow.c b/drivers/platform/x86/intel_menlow.c index 0a919d8..185a1bd 100644 --- a/drivers/platform/x86/intel_menlow.c +++ b/drivers/platform/x86/intel_menlow.c @@ -196,9 +196,13 @@ static int intel_menlow_memory_add(struct acpi_device *device) static int intel_menlow_memory_remove(struct acpi_device *device) { - struct thermal_cooling_device *cdev = acpi_driver_data(device); + struct thermal_cooling_device *cdev; + + if (!device) + return -EINVAL; - if (!device || !cdev) + cdev = acpi_driver_data(device); + if (!cdev) return -EINVAL; sysfs_remove_link(&device->dev.kobj, "thermal_cooling");