ACPI / fan: avoid null pointer deference error

Fix a null pointer deference by acpi_driver_data() if device is
null.  We should only set cdev and check this is OK after we are
sure device is not null.

Smatch analysis:

drivers/acpi/fan.c:179 acpi_fan_remove() warn: variable dereferenced
  before check 'device' (see line 177)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Colin Ian King 2013-03-25 10:50:05 +00:00 committed by Rafael J. Wysocki
parent 994fa63c5b
commit f0c29583db

View File

@ -174,9 +174,13 @@ static int acpi_fan_add(struct acpi_device *device)
static int acpi_fan_remove(struct acpi_device *device)
{
struct thermal_cooling_device *cdev = acpi_driver_data(device);
struct thermal_cooling_device *cdev;
if (!device || !cdev)
if (!device)
return -EINVAL;
cdev = acpi_driver_data(device);
if (!cdev)
return -EINVAL;
sysfs_remove_link(&device->dev.kobj, "thermal_cooling");