Return-Path: Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:56744 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932205AbcCAX4P (ORCPT ); Tue, 1 Mar 2016 18:56:15 -0500 Received: from pmta03.dal05.mailchimp.com (127.0.0.1) by mail333.us4.mandrillapp.com id hqom1u174non for ; Tue, 1 Mar 2016 23:54:22 +0000 (envelope-from ) From: Greg Kroah-Hartman Subject: [PATCH 4.4 114/342] mei: validate request value in client notify request ioctl To: Cc: Greg Kroah-Hartman , , Alexander Usyskin , Tomas Winkler Message-Id: <20160301234531.646082754@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> Date: Tue, 01 Mar 2016 23:54:22 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Usyskin commit 7326fffb712f09a315bc73cc1ee63843f59b8bd4 upstream. This patch address a possible security issue: The request field in client notify request ioctl comes from user space as u32 and is downcasted to u8 with out validation. Check request field to have approved values MEI_HBM_NOTIFICATION_STAR/STOP Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/main.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/misc/mei/main.c +++ b/drivers/misc/mei/main.c @@ -458,7 +458,11 @@ static int mei_ioctl_client_notify_reque { struct mei_cl *cl = file->private_data; - return mei_cl_notify_request(cl, file, request); + if (request != MEI_HBM_NOTIFICATION_START && + request != MEI_HBM_NOTIFICATION_STOP) + return -EINVAL; + + return mei_cl_notify_request(cl, file, (u8)request); } /**