From patchwork Fri Jan 12 00:47:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10160265 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 F301260327 for ; Fri, 12 Jan 2018 11:30:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DFA06207A7 for ; Fri, 12 Jan 2018 11:30:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D3F65285A5; Fri, 12 Jan 2018 11:30:38 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id D7209207A7 for ; Fri, 12 Jan 2018 11:30:37 +0000 (UTC) Received: (qmail 20416 invoked by uid 550); 12 Jan 2018 11:29:15 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Delivered-To: moderator for kernel-hardening@lists.openwall.com Received: (qmail 24502 invoked from network); 12 Jan 2018 00:56:02 -0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,346,1511856000"; d="scan'208";a="194314791" From: Dan Williams To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, alan@linux.intel.com, kernel-hardening@lists.openwall.com, Laurent Pinchart , tglx@linutronix.de, Mauro Carvalho Chehab , torvalds@linux-foundation.org, akpm@linux-foundation.org, Elena Reshetova , linux-media@vger.kernel.org Date: Thu, 11 Jan 2018 16:47:40 -0800 Message-ID: <151571806069.27429.6683179525235570687.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151571798296.27429.7166552848688034184.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151571798296.27429.7166552848688034184.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Subject: [kernel-hardening] [PATCH v2 14/19] [media] uvcvideo: prevent bounds-check bypass via speculative execution 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. Laurent notes: "...as this is nowhere close to being a fast path, I think we can close this potential hole as proposed in the patch" Cc: Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org Reviewed-by: Laurent Pinchart Signed-off-by: Elena Reshetova Signed-off-by: Dan Williams --- drivers/media/usb/uvc/uvc_v4l2.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c index 3e7e283a44a8..30ee200206ee 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 @@ -809,8 +810,12 @@ static int uvc_ioctl_enum_input(struct file *file, void *fh, const struct uvc_entity *selector = chain->selector; struct uvc_entity *iterm = NULL; u32 index = input->index; + __u8 *elem = NULL; int pin = 0; + if (selector) + elem = array_ptr(selector->baSourceID, index, + selector->bNrInPins); if (selector == NULL || (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { if (index != 0) @@ -820,8 +825,8 @@ 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) { + pin = *elem; list_for_each_entry(iterm, &chain->entities, chain) { if (!UVC_ENTITY_IS_ITERM(iterm)) continue;