From patchwork Sat May 19 01:13:42 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: 10412449 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 741BF601F9 for ; Sat, 19 May 2018 01:36:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6F18628AFC for ; Sat, 19 May 2018 01:36:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6269A28B09; Sat, 19 May 2018 01:36:19 +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=unavailable 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 D50FC28AFC for ; Sat, 19 May 2018 01:36:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751888AbeESBgP (ORCPT ); Fri, 18 May 2018 21:36:15 -0400 Received: from gateway36.websitewelcome.com ([192.185.199.121]:47026 "EHLO gateway36.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957AbeESBgP (ORCPT ); Fri, 18 May 2018 21:36:15 -0400 Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway36.websitewelcome.com (Postfix) with ESMTP id 34197400E1336 for ; Fri, 18 May 2018 20:13:44 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id JqRMfOEDLWCOCJqRMfEdPt; Fri, 18 May 2018 20:13:44 -0500 X-Authority-Reason: nr=8 Received: from [187.172.56.86] (port=58738 helo=embeddedgus) by gator4166.hostgator.com with esmtpa (Exim 4.89_1) (envelope-from ) id 1fJqRL-004N6K-La; Fri, 18 May 2018 20:13:43 -0500 Date: Fri, 18 May 2018 20:13:42 -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 v3] usbip: vhci_sysfs: fix potential Spectre v1 Message-ID: <20180519011342.GA13962@embeddedgus> 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: 187.172.56.86 X-Source-L: No X-Exim-ID: 1fJqRL-004N6K-La X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [187.172.56.86]:58738 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 Acked-by: Shuah Khan (Samsung OSG) --- Changes in v3: - Pass the addresses of pdev_nr and rhport into valid_port and valid_args. Changes in v2: - Place the barriers into valid_port. drivers/usb/usbip/vhci_sysfs.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c index 4880838..be37aec 100644 --- a/drivers/usb/usbip/vhci_sysfs.c +++ b/drivers/usb/usbip/vhci_sysfs.c @@ -10,6 +10,9 @@ #include #include +/* Hardening for Spectre-v1 */ +#include + #include "usbip_common.h" #include "vhci.h" @@ -205,16 +208,20 @@ static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport) return 0; } -static int valid_port(__u32 pdev_nr, __u32 rhport) +static int valid_port(__u32 *pdev_nr, __u32 *rhport) { - if (pdev_nr >= vhci_num_controllers) { - pr_err("pdev %u\n", pdev_nr); + if (*pdev_nr >= vhci_num_controllers) { + pr_err("pdev %u\n", *pdev_nr); return 0; } - if (rhport >= VHCI_HC_PORTS) { - pr_err("rhport %u\n", rhport); + *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; } @@ -232,7 +239,7 @@ static ssize_t detach_store(struct device *dev, struct device_attribute *attr, pdev_nr = port_to_pdev_nr(port); rhport = port_to_rhport(port); - if (!valid_port(pdev_nr, rhport)) + if (!valid_port(&pdev_nr, &rhport)) return -EINVAL; hcd = platform_get_drvdata(vhcis[pdev_nr].pdev); @@ -258,7 +265,8 @@ static ssize_t detach_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_WO(detach); -static int valid_args(__u32 pdev_nr, __u32 rhport, enum usb_device_speed speed) +static int valid_args(__u32 *pdev_nr, __u32 *rhport, + enum usb_device_speed speed) { if (!valid_port(pdev_nr, rhport)) { return 0; @@ -322,7 +330,7 @@ static ssize_t attach_store(struct device *dev, struct device_attribute *attr, sockfd, devid, speed); /* check received parameters */ - if (!valid_args(pdev_nr, rhport, speed)) + if (!valid_args(&pdev_nr, &rhport, speed)) return -EINVAL; hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);