[stable] 2.6.27.y: fix NULL ptr deref in cx23885 video_open
Commit Message
Can we have this merged into -stable? Jarod Wilson sent this last
month, but he left off the cc to stable@kernel.org
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
---------- Forwarded message ----------
From: Jarod Wilson <jarod@redhat.com>
Date: Tue, Feb 24, 2009 at 6:00 PM
Subject: [stable] [PATCH] 2.6.27.y: fix NULL ptr deref in cx23885 video_open
To: linux-kernel@vger.kernel.org
Cc: Mike Krufky <mkrufky@linuxtv.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 <jarod@redhat.com>
Reviewed-by: Michael Krufky <mkrufky@linuxtv.org>
---
drivers/media/video/cx23885/cx23885-417.c | 2 +-
drivers/media/video/cx23885/cx23885-video.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
}
--
Jarod Wilson
jarod@redhat.com
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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;
}
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;