[PATCH 8/11] drivers/media: Eliminate a NULL pointer dereference

From: Julia Lawall
Date: Thu May 27 2010 - 08:36:57 EST


From: Julia Lawall <julia@xxxxxxx>

In each case, the print involves dereferencing a value that is NULL or is
near NULL.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@

if ((E == NULL && ...) || ...)
{
... when != if (...) S1 else S2
when != E = E1
* E->f
... when any
return ...;
}
else S3
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/media/dvb/firewire/firedtv-1394.c | 2 +-
drivers/media/video/hdpvr/hdpvr-video.c | 2 +-
drivers/media/video/usbvision/usbvision-video.c | 3 +--
3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/media/video/usbvision/usbvision-video.c b/drivers/media/video/usbvision/usbvision-video.c
index 6248a63..c2690df 100644
--- a/drivers/media/video/usbvision/usbvision-video.c
+++ b/drivers/media/video/usbvision/usbvision-video.c
@@ -1671,8 +1671,7 @@ static void __devexit usbvision_disconnect(struct usb_interface *intf)
PDEBUG(DBG_PROBE, "");

if (usbvision == NULL) {
- dev_err(&usbvision->dev->dev,
- "%s: usb_get_intfdata() failed\n", __func__);
+ pr_err("%s: usb_get_intfdata() failed\n", __func__);
return;
}

diff --git a/drivers/media/video/hdpvr/hdpvr-video.c b/drivers/media/video/hdpvr/hdpvr-video.c
index 7cfccfd..c338f3f 100644
--- a/drivers/media/video/hdpvr/hdpvr-video.c
+++ b/drivers/media/video/hdpvr/hdpvr-video.c
@@ -366,7 +366,7 @@ static int hdpvr_open(struct file *file)

dev = (struct hdpvr_device *)video_get_drvdata(video_devdata(file));
if (!dev) {
- v4l2_err(&dev->v4l2_dev, "open failing with with ENODEV\n");
+ pr_err("open failing with with ENODEV\n");
retval = -ENODEV;
goto err;
}
diff --git a/drivers/media/dvb/firewire/firedtv-1394.c b/drivers/media/dvb/firewire/firedtv-1394.c
index 26333b4..b34ca7a 100644
--- a/drivers/media/dvb/firewire/firedtv-1394.c
+++ b/drivers/media/dvb/firewire/firedtv-1394.c
@@ -58,7 +58,7 @@ static void rawiso_activity_cb(struct hpsb_iso *iso)
num = hpsb_iso_n_ready(iso);

if (!fdtv) {
- dev_err(fdtv->device, "received at unknown iso channel\n");
+ pr_err("received at unknown iso channel\n");
goto out;
}

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