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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIMWL_WL_HIGH, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 3F309C433EF for ; Thu, 14 Jun 2018 14:48:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E677B208CB for ; Thu, 14 Jun 2018 14:48:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="wUk+vsEd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E677B208CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755471AbeFNOsL (ORCPT ); Thu, 14 Jun 2018 10:48:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:48120 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965099AbeFNOHp (ORCPT ); Thu, 14 Jun 2018 10:07:45 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 16FBF208DA; Thu, 14 Jun 2018 14:07:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1528985264; bh=5eK0SNaaqbJogctCI/B2QUYxh9aQHwPIGZzNZ2b89g8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wUk+vsEduAY3zMoNwwZNIz08q14Y4oMCFOQ/hHfnGd6caDttCcw8u6f2M1Vn28flv kw3RVcEw+ZudiFJRAEIR+hF9frfTubGmnz45xWvMI2aQ+dyGf4JINxrw9vJGzJScBf eqEYZwUYrDaEpvRCKwLF7Zc2XzgoiVwQv1jO40BM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Gustavo A. R. Silva" , "Shuah Khan (Samsung OSG)" Subject: [PATCH 4.16 11/43] usbip: vhci_sysfs: fix potential Spectre v1 Date: Thu, 14 Jun 2018 16:04:15 +0200 Message-Id: <20180614132135.586620724@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180614132135.111973468@linuxfoundation.org> References: <20180614132135.111973468@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit a0d6ec88090d7b1b008429c44532a388e29bb1bd upstream. 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) Signed-off-by: Greg Kroah-Hartman --- drivers/usb/usbip/vhci_sysfs.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) --- 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 v 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 devic 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 devic } 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 devic 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);