From patchwork Fri Jun 29 22:08:44 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: 10497699 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 16806602CC for ; Fri, 29 Jun 2018 22:31:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DD468296DB for ; Fri, 29 Jun 2018 22:31:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CD12A296EC; Fri, 29 Jun 2018 22:31:27 +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 BF599296DB for ; Fri, 29 Jun 2018 22:31:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933062AbeF2WbZ (ORCPT ); Fri, 29 Jun 2018 18:31:25 -0400 Received: from gateway24.websitewelcome.com ([192.185.51.202]:36764 "EHLO gateway24.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932740AbeF2WbY (ORCPT ); Fri, 29 Jun 2018 18:31:24 -0400 X-Greylist: delayed 1344 seconds by postgrey-1.27 at vger.kernel.org; Fri, 29 Jun 2018 18:31:24 EDT Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway24.websitewelcome.com (Postfix) with ESMTP id ADCE7A123 for ; Fri, 29 Jun 2018 17:08:59 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id Z1ZNfDsGeaSeyZ1ZVftBlD; Fri, 29 Jun 2018 17:08:58 -0500 X-Authority-Reason: nr=8 Received: from [189.250.65.56] (port=49300 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1fZ1ZN-002uFN-3a; Fri, 29 Jun 2018 17:08:45 -0500 Date: Fri, 29 Jun 2018 17:08:44 -0500 From: "Gustavo A. R. Silva" To: Jiri Kosina , Benjamin Tissoires Cc: linux-usb@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] HID: hiddev: fix potential Spectre v1 Message-ID: <20180629220844.GA13823@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: 189.250.65.56 X-Source-L: No X-Exim-ID: 1fZ1ZN-002uFN-3a X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.65.56]:49300 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 3 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 uref->field_index, uref->usage_index, finfo.field_index and cinfo.index can be indirectly 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/hid/usbhid/hiddev.c:473 hiddev_ioctl_usage() warn: potential spectre issue 'report->field' (local cap) drivers/hid/usbhid/hiddev.c:477 hiddev_ioctl_usage() warn: potential spectre issue 'field->usage' (local cap) drivers/hid/usbhid/hiddev.c:757 hiddev_ioctl() warn: potential spectre issue 'report->field' (local cap) drivers/hid/usbhid/hiddev.c:801 hiddev_ioctl() warn: potential spectre issue 'hid->collection' (local cap) Fix this by sanitizing such structure fields before using them to index report->field, field->usage and hid->collection 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 --- drivers/hid/usbhid/hiddev.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index e3ce233..23872d0 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "usbhid.h" #ifdef CONFIG_USB_DYNAMIC_MINORS @@ -469,10 +470,14 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, if (uref->field_index >= report->maxfield) goto inval; + uref->field_index = array_index_nospec(uref->field_index, + report->maxfield); field = report->field[uref->field_index]; if (uref->usage_index >= field->maxusage) goto inval; + uref->usage_index = array_index_nospec(uref->usage_index, + field->maxusage); uref->usage_code = field->usage[uref->usage_index].hid; @@ -499,6 +504,8 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, if (uref->field_index >= report->maxfield) goto inval; + uref->field_index = array_index_nospec(uref->field_index, + report->maxfield); field = report->field[uref->field_index]; @@ -753,6 +760,8 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (finfo.field_index >= report->maxfield) break; + finfo.field_index = array_index_nospec(finfo.field_index, + report->maxfield); field = report->field[finfo.field_index]; memset(&finfo, 0, sizeof(finfo)); @@ -797,6 +806,8 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (cinfo.index >= hid->maxcollection) break; + cinfo.index = array_index_nospec(cinfo.index, + hid->maxcollection); cinfo.type = hid->collection[cinfo.index].type; cinfo.usage = hid->collection[cinfo.index].usage;