From: Julia Lawall <julia@diku.dk>
Date: Tue, 6 Apr 2010 05:51:04 +0000 (-0300)
Subject: V4L/DVB: drivers/media/video: avoid NULL dereference
X-Git-Tag: v2.6.35-rc1~480^2~257
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=e20144770f5a119516f93959eca9818fa5ff065e

V4L/DVB: drivers/media/video: avoid NULL dereference

It seems impossible for ov to be NULL at this point.

The semantic match that finds the problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E, E1;
identifier f;
statement S1,S3;
iterator iter;
@@

if ((E == NULL && ...) || ...)
{
  ... when != false ((E == NULL && ...) || ...)
      when != true  ((E != NULL && ...) || ...)
      when != iter(E,...) S1
      when != E = E1
(
  sizeof(E->f)
|
* E->f
)
  ... when any
  return ...;
}
else S3
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---

diff --git a/drivers/media/video/ov511.c b/drivers/media/video/ov511.c
index e0bce8d..dd1b1ac 100644
--- a/drivers/media/video/ov511.c
+++ b/drivers/media/video/ov511.c
@@ -5916,11 +5916,6 @@ ov51x_disconnect(struct usb_interface *intf)
 	mutex_lock(&ov->lock);
 	usb_set_intfdata (intf, NULL);
 
-	if (!ov) {
-		mutex_unlock(&ov->lock);
-		return;
-	}
-
 	/* Free device number */
 	ov511_devused &= ~(1 << ov->nr);