From patchwork Thu May 17 20:16:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 10407759 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 513BF60230 for ; Thu, 17 May 2018 21:02:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3FA512875C for ; Thu, 17 May 2018 21:02:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 31F5828760; Thu, 17 May 2018 21:02:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C2CFE2875C for ; Thu, 17 May 2018 21:02:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751626AbeEQVCj (ORCPT ); Thu, 17 May 2018 17:02:39 -0400 Received: from gateway20.websitewelcome.com ([192.185.66.3]:38388 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbeEQVCi (ORCPT ); Thu, 17 May 2018 17:02:38 -0400 X-Greylist: delayed 1500 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 May 2018 17:02:38 EDT Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway20.websitewelcome.com (Postfix) with ESMTP id F09D5400CE533 for ; Thu, 17 May 2018 15:16:29 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id JPK9fetSMBcCXJPK9fakrE; Thu, 17 May 2018 15:16:29 -0500 X-Authority-Reason: nr=8 Received: from cablelink20-167.telefonia.intercable.net ([201.172.20.167]:57166 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.89_1) (envelope-from ) id 1fJPK9-0011mL-8i; Thu, 17 May 2018 15:16:29 -0500 Date: Thu, 17 May 2018 15:16:28 -0500 From: "Gustavo A. R. Silva" To: Valentina Manea , Shuah Khan , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH v2] usbip: vhci_sysfs: fix potential Spectre v1 Message-ID: <20180517201628.GA6090@embeddedor.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.172.20.167 X-Source-L: No X-Exim-ID: 1fJPK9-0011mL-8i X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: cablelink20-167.telefonia.intercable.net (embeddedor) [201.172.20.167]:57166 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 4 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP pdev_nr and rhport can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/usb/usbip/vhci_sysfs.c:238 detach_store() warn: potential spectre issue 'vhcis' drivers/usb/usbip/vhci_sysfs.c:328 attach_store() warn: potential spectre issue 'vhcis' drivers/usb/usbip/vhci_sysfs.c:338 attach_store() warn: potential spectre issue 'vhci->vhci_hcd_ss->vdev' drivers/usb/usbip/vhci_sysfs.c:340 attach_store() warn: potential spectre issue 'vhci->vhci_hcd_hs->vdev' Fix this by sanitizing pdev_nr and rhport before using them to index vhcis and vhci->vhci_hcd_ss->vdev respectively. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - Place the barriers into valid_port. drivers/usb/usbip/vhci_sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c index 4880838..69db0c9 100644 --- a/drivers/usb/usbip/vhci_sysfs.c +++ b/drivers/usb/usbip/vhci_sysfs.c @@ -10,6 +10,8 @@ #include #include +#include + #include "usbip_common.h" #include "vhci.h" @@ -211,10 +213,14 @@ static int valid_port(__u32 pdev_nr, __u32 rhport) pr_err("pdev %u\n", pdev_nr); return 0; } + pdev_nr = array_index_nospec(pdev_nr, vhci_num_controllers); + if (rhport >= VHCI_HC_PORTS) { pr_err("rhport %u\n", rhport); return 0; } + rhport = array_index_nospec(rhport, VHCI_HC_PORTS); + return 1; }