ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()

After commit fa1675b (ACPI / PM: Rework and clean up
acpi_dev_pm_get_state()) a NULL pointer dereference will take place
if NULL is passed to acpi_pm_device_sleep_state() as the second
argument.

Fix that by avoiding to use the pointer that may be NULL until
it's necessary to store a return value at the location pointed to
by it (if not NULL).

Reported-and-tested-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2013-06-27 14:01:02 +02:00
parent fa1675b565
commit 9b5c7a5a97
1 changed files with 8 additions and 4 deletions

View File

@ -521,7 +521,7 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
struct acpi_device *adev;
int ret, d_max;
int ret, d_min, d_max;
if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
return -EINVAL;
@ -540,19 +540,23 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
}
ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
d_min_p, &d_max);
&d_min, &d_max);
if (ret)
return ret;
if (d_max_in < *d_min_p)
if (d_max_in < d_min)
return -EINVAL;
if (d_max > d_max_in) {
for (d_max = d_max_in; d_max > *d_min_p; d_max--) {
for (d_max = d_max_in; d_max > d_min; d_max--) {
if (adev->power.states[d_max].flags.valid)
break;
}
}
if (d_min_p)
*d_min_p = d_min;
return d_max;
}
EXPORT_SYMBOL(acpi_pm_device_sleep_state);