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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFD5BC43441 for ; Mon, 19 Nov 2018 16:58:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8B3D2148E for ; Mon, 19 Nov 2018 16:58:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="csusB0P9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8B3D2148E 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 S2404755AbeKTDW3 (ORCPT ); Mon, 19 Nov 2018 22:22:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:34138 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403834AbeKTDW2 (ORCPT ); Mon, 19 Nov 2018 22:22:28 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 4B7B62148E; Mon, 19 Nov 2018 16:58:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542646692; bh=FhAY5101g+bMmXjSTGJ/eDAU7wF8/oPjo1p80Udpk40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=csusB0P9RVRUZWJ5aFbqvm0Ekht4TKObtHs9H97XrOSvOk3WZ74BDKljC4xZfxsQd KHHTQ9T5Mx3v2AGuAE5Vw14p5hLmn9oE8pDXJMreQ2V+Pt9JUFYjW1o1Yu6zYFIK18 +wx1G3OGJEVjV3k1/94ijz/fzSga+cppbUeTEpV4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Breno Leitao , Jiri Kosina Subject: [PATCH 4.4 053/160] HID: hiddev: fix potential Spectre v1 Date: Mon, 19 Nov 2018 17:28:12 +0100 Message-Id: <20181119162636.676152532@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162630.031306128@linuxfoundation.org> References: <20181119162630.031306128@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Breno Leitao commit f11274396a538b31bc010f782e05c2ce3f804c13 upstream. uref->usage_index can be indirectly controlled by userspace, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This field is used as an array index by the hiddev_ioctl_usage() function, when 'cmd' is either HIDIOCGCOLLECTIONINDEX, HIDIOCGUSAGES or HIDIOCSUSAGES. For cmd == HIDIOCGCOLLECTIONINDEX case, uref->usage_index is compared to field->maxusage and then used as an index to dereference field->usage array. The same thing happens to the cmd == HIDIOC{G,S}USAGES cases, where uref->usage_index is checked against an array maximum value and then it is used as an index in an array. This is a summary of the HIDIOCGCOLLECTIONINDEX case, which matches the traditional Spectre V1 first load: copy_from_user(uref, user_arg, sizeof(*uref)) if (uref->usage_index >= field->maxusage) goto inval; i = field->usage[uref->usage_index].collection_index; return i; This patch fixes this by sanitizing field uref->usage_index before using it to index field->usage (HIDIOCGCOLLECTIONINDEX) or field->value in HIDIOC{G,S}USAGES arrays, thus, avoiding speculation in the first load. Cc: Signed-off-by: Breno Leitao v2: Contemplate cmd == HIDIOC{G,S}USAGES case Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/usbhid/hiddev.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -521,14 +521,24 @@ static noinline int hiddev_ioctl_usage(s if (cmd == HIDIOCGCOLLECTIONINDEX) { if (uref->usage_index >= field->maxusage) goto inval; + uref->usage_index = + array_index_nospec(uref->usage_index, + field->maxusage); } else if (uref->usage_index >= field->report_count) goto inval; } - if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) && - (uref_multi->num_values > HID_MAX_MULTI_USAGES || - uref->usage_index + uref_multi->num_values > field->report_count)) - goto inval; + if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) { + if (uref_multi->num_values > HID_MAX_MULTI_USAGES || + uref->usage_index + uref_multi->num_values > + field->report_count) + goto inval; + + uref->usage_index = + array_index_nospec(uref->usage_index, + field->report_count - + uref_multi->num_values); + } switch (cmd) { case HIDIOCGUSAGE: