From patchwork Wed Jan 7 20:52:57 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 5588231 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@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 35CF0BF6C3 for ; Wed, 7 Jan 2015 20:56:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5586E20389 for ; Wed, 7 Jan 2015 20:56:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6788E20382 for ; Wed, 7 Jan 2015 20:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755467AbbAGU41 (ORCPT ); Wed, 7 Jan 2015 15:56:27 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:38385 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755047AbbAGUxP (ORCPT ); Wed, 7 Jan 2015 15:53:15 -0500 Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id t07Kr7SC020698 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 7 Jan 2015 20:53:08 GMT Received: from aserz7022.oracle.com (aserz7022.oracle.com [141.146.126.231]) by acsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id t07Kr6eO011532 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Wed, 7 Jan 2015 20:53:07 GMT Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by aserz7022.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id t07Kr6UB011527; Wed, 7 Jan 2015 20:53:06 GMT Received: from lappy.hsd1.nh.comcast.net (/10.154.190.34) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 07 Jan 2015 12:53:06 -0800 From: Sasha Levin To: linux-kernel@vger.kernel.org Cc: Sasha Levin , , Alex Williamson , Bjorn Helgaas , Konrad Rzeszutek Wilk , Alexander Graf , Greg Kroah-Hartman , linux-pci@vger.kernel.org (open list:PCI SUBSYSTEM) Subject: [PATCH v2] PCI/sysfs: off by two when checking the limit on driver_override length Date: Wed, 7 Jan 2015 15:52:57 -0500 Message-Id: <1420663977-30707-1-git-send-email-sasha.levin@oracle.com> X-Mailer: git-send-email 2.1.0 X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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 When printing the driver_override parameter when it is 4095 and 4094 bytes long the printing code would access invalid memory because we need count+1 bytes for printing. Cc: # v3.16+ Fixes: 782a985d ("PCI: Introduce new device binding path using pci_dev.driver_override") Cc: Alex Williamson Cc: Bjorn Helgaas Cc: Konrad Rzeszutek Wilk Cc: Alexander Graf Cc: Greg Kroah-Hartman Signed-off-by: Sasha Levin Acked-by: Alex Williamson --- drivers/pci/pci-sysfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index aa012fb..17459ed 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -521,7 +521,8 @@ static ssize_t driver_override_store(struct device *dev, struct pci_dev *pdev = to_pci_dev(dev); char *driver_override, *old = pdev->driver_override, *cp; - if (count > PATH_MAX) + /* We need to keep extra room for a newline */ + if (count >= (PATH_MAX - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL);