From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760914AbZBXWBU (ORCPT ); Tue, 24 Feb 2009 17:01:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755187AbZBXWBL (ORCPT ); Tue, 24 Feb 2009 17:01:11 -0500 Received: from mx2.redhat.com ([66.187.237.31]:43031 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753543AbZBXWBJ (ORCPT ); Tue, 24 Feb 2009 17:01:09 -0500 From: Jarod Wilson Organization: Red Hat, Inc. To: linux-kernel@vger.kernel.org Subject: [stable] [PATCH] 2.6.27.y: fix NULL ptr deref in cx23885 video_open Date: Tue, 24 Feb 2009 17:00:55 -0500 User-Agent: KMail/1.11.0 (Linux/2.6.27.18-171.2.28.fc10.x86_64; KDE/4.2.0; x86_64; ; ) Cc: Mike Krufky MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200902241700.56099.jarod@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark Jenks https://www.redhat.com/mailman/private/video4linux-list/2009-January/msg00041.html The Hauppauge WinTV HVR-1800 tv tuner card has both digital and analog abilities, both of which are supported by v4l/dvb under 2.6.27.y. The analog side also features a hardware mpeg2 encoder. The HVR-1250 tv tuner card has both digital and analog abilities, but analog isn't currently supported under any kernel. These cards both utilize the cx23885 driver, but with slightly different usage. When the code paths for each card is executed, they wind up poking a cx23885_devlist, which contains devices from both of the cards, and access attempts are made to portions of 'struct cx23885_dev' that aren't valid for that device. Simply add some extra checks before trying to access these structs. More gory details: http://article.gmane.org/gmane.linux.drivers.dvb/46630 This was triggering on my own system at home w/both cards in it, and no longer happens with this patch included. Signed-off-by: Jarod Wilson Reviewed-by: Michael Krufky --- drivers/media/video/cx23885/cx23885-417.c | 2 +- drivers/media/video/cx23885/cx23885-video.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/video/cx23885/cx23885-417.c b/drivers/media/video/cx23885/cx23885-417.c index 7b0e8c0..19154b6 100644 --- a/drivers/media/video/cx23885/cx23885-417.c +++ b/drivers/media/video/cx23885/cx23885-417.c @@ -1585,7 +1585,7 @@ static int mpeg_open(struct inode *inode, struct file *file) list_for_each(list, &cx23885_devlist) { h = list_entry(list, struct cx23885_dev, devlist); - if (h->v4l_device->minor == minor) { + if (h->v4l_device && h->v4l_device->minor == minor) { dev = h; break; } diff --git a/drivers/media/video/cx23885/cx23885-video.c b/drivers/media/video/cx23885/cx23885-video.c index 6047c78..a2b5a0c 100644 --- a/drivers/media/video/cx23885/cx23885-video.c +++ b/drivers/media/video/cx23885/cx23885-video.c @@ -733,7 +733,7 @@ static int video_open(struct inode *inode, struct file *file) list_for_each(list, &cx23885_devlist) { h = list_entry(list, struct cx23885_dev, devlist); - if (h->video_dev->minor == minor) { + if (h->video_dev && h->video_dev->minor == minor) { dev = h; type = V4L2_BUF_TYPE_VIDEO_CAPTURE; } -- Jarod Wilson jarod@redhat.com