ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()

Commit e1acdeb0e7 "ACPI / scan: Simplify acpi_match_device()"
introduced code that may lead to a NULL pointer dereference when
trying to unlock a mutex.  Fix that.

Fixes: e1acdeb0e7 "ACPI / scan: Simplify acpi_match_device()"
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2015-04-13 21:35:51 +02:00
parent 8765c5ba19
commit 5f2e3274e5

View file

@ -247,6 +247,7 @@ static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
static struct acpi_device *acpi_companion_match(const struct device *dev)
{
struct acpi_device *adev;
struct mutex *physical_node_lock;
adev = ACPI_COMPANION(dev);
if (!adev)
@ -255,7 +256,8 @@ static struct acpi_device *acpi_companion_match(const struct device *dev)
if (list_empty(&adev->pnp.ids))
return NULL;
mutex_lock(&adev->physical_node_lock);
physical_node_lock = &adev->physical_node_lock;
mutex_lock(physical_node_lock);
if (list_empty(&adev->physical_node_list)) {
adev = NULL;
} else {
@ -266,7 +268,7 @@ static struct acpi_device *acpi_companion_match(const struct device *dev)
if (node->dev != dev)
adev = NULL;
}
mutex_unlock(&adev->physical_node_lock);
mutex_unlock(physical_node_lock);
return adev;
}