From patchwork Sat Jan 6 01:10:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10147463 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 8B12A60155 for ; Sat, 6 Jan 2018 01:22:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C226A28988 for ; Sat, 6 Jan 2018 01:22:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B5F06289BE; Sat, 6 Jan 2018 01:22:42 +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=-6.9 required=2.0 tests=BAYES_00,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 4831228988 for ; Sat, 6 Jan 2018 01:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753769AbeAFBSu (ORCPT ); Fri, 5 Jan 2018 20:18:50 -0500 Received: from mga05.intel.com ([192.55.52.43]:34280 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753763AbeAFBSr (ORCPT ); Fri, 5 Jan 2018 20:18:47 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Jan 2018 17:18:46 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,320,1511856000"; d="scan'208";a="21819327" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga001.jf.intel.com with ESMTP; 05 Jan 2018 17:18:46 -0800 Subject: [PATCH 07/18] [media] uvcvideo: prevent bounds-check bypass via speculative execution From: Dan Williams To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, alan@linux.intel.com, peterz@infradead.org, netdev@vger.kernel.org, Laurent Pinchart , gregkh@linuxfoundation.org, tglx@linutronix.de, Mauro Carvalho Chehab , torvalds@linux-foundation.org, Elena Reshetova , linux-media@vger.kernel.org Date: Fri, 05 Jan 2018 17:10:32 -0800 Message-ID: <151520103240.32271.14706852449205864676.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151520099201.32271.4677179499894422956.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151520099201.32271.4677179499894422956.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Static analysis reports that 'index' may be a user controlled value that is used as a data dependency to read 'pin' from the 'selector->baSourceID' array. In order to avoid potential leaks of kernel memory values, block speculative execution of the instruction stream that could issue reads based on an invalid value of 'pin'. Based on an original patch by Elena Reshetova. Cc: Laurent Pinchart Cc: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org Signed-off-by: Elena Reshetova Signed-off-by: Dan Williams Reviewed-by: Laurent Pinchart --- drivers/media/usb/uvc/uvc_v4l2.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c index 3e7e283a44a8..7442626dc20e 100644 --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -810,6 +811,7 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh, struct uvc_entity *iterm = NULL; u32 index = input->index; int pin = 0; + __u8 *elem; if (selector == NULL || (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { @@ -820,8 +822,9 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh, break; } pin = iterm->id; - } else if (index < selector->bNrInPins) { - pin = selector->baSourceID[index]; + } else if ((elem = nospec_array_ptr(selector->baSourceID, index, + selector->bNrInPins))) { + pin = *elem; list_for_each_entry(iterm, &chain->entities, chain) { if (!UVC_ENTITY_IS_ITERM(iterm)) continue;