From: Colin Ian King <colin.king@canonical.com>
Date: Mon, 25 Mar 2013 10:50:05 +0000 (+0000)
Subject: ACPI / fan: avoid null pointer deference error
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f0c29583db51104a7bc223b1e9c88d818f24ba4d;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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>
---

diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index f815da82c765..8d1c0105e113 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");