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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-06-27 16:01:02 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-06-28 14:55:59 +0400
commit9b5c7a5a977a330ffaf83c4d383ba247c74c800f (patch)
tree43dbd7adfaf40ad4cab7b0d20c2c9bb4c4c01615
parentfa1675b56537651270e79967b7f1ee4202c83bf6 (diff)
downloadlinux-9b5c7a5a977a330ffaf83c4d383ba247c74c800f.tar.xz
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>
-rw-r--r--drivers/acpi/device_pm.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index fd363b57a596..4c56dc830ebc 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -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);