From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752127AbcFEKxS (ORCPT ); Sun, 5 Jun 2016 06:53:18 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21709 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751977AbcFEKVl (ORCPT ); Sun, 5 Jun 2016 06:21:41 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oliver Neukum , Oliver Neukum , Greg Kroah-Hartman , Willy Tarreau Subject: [PATCH 3.10 018/143] USB: cdc-acm: more sanity checking Date: Sun, 5 Jun 2016 12:18:41 +0200 Message-Id: <1465122046-9645-19-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oliver Neukum commit 8835ba4a39cf53f705417b3b3a94eb067673f2c9 upstream. An attack has become available which pretends to be a quirky device circumventing normal sanity checks and crashes the kernel by an insufficient number of interfaces. This patch adds a check to the code path for quirky devices. Signed-off-by: Oliver Neukum CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- drivers/usb/class/cdc-acm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index d6dab8a..e7436eb 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -997,6 +997,9 @@ static int acm_probe(struct usb_interface *intf, if (quirks == NO_UNION_NORMAL) { data_interface = usb_ifnum_to_if(usb_dev, 1); control_interface = usb_ifnum_to_if(usb_dev, 0); + /* we would crash */ + if (!data_interface || !control_interface) + return -ENODEV; goto skip_normal_probe; } -- 2.8.0.rc2.1.gbe9624a