From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034004AbdEWVA0 (ORCPT ); Tue, 23 May 2017 17:00:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56020 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033317AbdEWVAT (ORCPT ); Tue, 23 May 2017 17:00:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tobias Herzog , Oliver Neukum Subject: [PATCH 3.18 13/59] cdc-acm: fix possible invalid access when processing notification Date: Tue, 23 May 2017 22:09:41 +0200 Message-Id: <20170523200850.150930063@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200849.241966497@linuxfoundation.org> References: <20170523200849.241966497@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tobias Herzog commit 1bb9914e1730417d530de9ed37e59efdc647146b upstream. Notifications may only be 8 bytes long. Accessing the 9th and 10th byte of unimplemented/unknown notifications may be insecure. Also check the length of known notifications before accessing anything behind the 8th byte. Signed-off-by: Tobias Herzog Acked-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -315,6 +315,12 @@ static void acm_ctrl_irq(struct urb *urb break; case USB_CDC_NOTIFY_SERIAL_STATE: + if (le16_to_cpu(dr->wLength) != 2) { + dev_dbg(&acm->control->dev, + "%s - malformed serial state\n", __func__); + break; + } + newctrl = get_unaligned_le16(data); if (!acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) { @@ -351,11 +357,10 @@ static void acm_ctrl_irq(struct urb *urb default: dev_dbg(&acm->control->dev, - "%s - unknown notification %d received: index %d " - "len %d data0 %d data1 %d\n", + "%s - unknown notification %d received: index %d len %d\n", __func__, - dr->bNotificationType, dr->wIndex, - dr->wLength, data[0], data[1]); + dr->bNotificationType, dr->wIndex, dr->wLength); + break; } exit: