From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756528Ab2IIXY7 (ORCPT ); Sun, 9 Sep 2012 19:24:59 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51395 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756201Ab2IIXQw (ORCPT ); Sun, 9 Sep 2012 19:16:52 -0400 Message-Id: <20120909224157.635637419@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 09 Sep 2012 23:42:40 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Sven Schnelle , Greg Kroah-Hartman Subject: [ 50/95] USB: CDC ACM: Fix NULL pointer dereference In-Reply-To: <20120909224150.641491654@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Schnelle commit 99f347caa4568cb803862730b3b1f1942639523f upstream. If a device specifies zero endpoints in its interface descriptor, the kernel oopses in acm_probe(). Even though that's clearly an invalid descriptor, we should test wether we have all endpoints. This is especially bad as this oops can be triggered by just plugging a USB device in. Signed-off-by: Sven Schnelle Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/usb/class/cdc-acm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 56d6bf6..f763ed7 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1104,7 +1104,8 @@ skip_normal_probe: } - if (data_interface->cur_altsetting->desc.bNumEndpoints < 2) + if (data_interface->cur_altsetting->desc.bNumEndpoints < 2 || + control_interface->cur_altsetting->desc.bNumEndpoints == 0) return -EINVAL; epctrl = &control_interface->cur_altsetting->endpoint[0].desc;