diff mbox

[1/2] ACPI / fan: avoid null pointer deference error

Message ID 1364208606-8446-2-git-send-email-colin.king@canonical.com (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Colin King March 25, 2013, 10:50 a.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

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>
---
 drivers/acpi/fan.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index f815da8..8d1c010 100644
--- a/drivers/acpi/fan.c
+++ b/drivers/acpi/fan.c
@@ -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)
+		return -EINVAL;
 
-	if (!device || !cdev)
+	cdev =  acpi_driver_data(device);
+	if (!cdev)
 		return -EINVAL;
 
 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");