From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
In principle, it should be valid to pass NULL as the ACPI device
pointer to acpi_device_get_power() and acpi_device_set_power() and they
both are expected to return -EINVAL in that case, but that has been
broken recently by commit 62fcb99bdf10 ("ACPI: Drop parent field from
struct acpi_device") which has caused the ACPI device pointer to be
dereferenced in these functions before the NULL check.
Fix that and while at it make acpi_device_set_power() only use the
parent field if the target ACPI device object's ignore_parent flag
in not set.
Fixes: 62fcb99bdf10 ("ACPI: Drop parent field from struct acpi_device")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
linux-next material.
---
drivers/acpi/device_pm.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -74,13 +74,15 @@ static int acpi_dev_pm_explicit_get(stru
*/
int acpi_device_get_power(struct acpi_device *device, int *state)
{
- struct acpi_device *parent = acpi_dev_parent(device);
int result = ACPI_STATE_UNKNOWN;
+ struct acpi_device *parent;
int error;
if (!device || !state)
return -EINVAL;
+ parent = acpi_dev_parent(device);
+
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = parent ? parent->power.state : ACPI_STATE_D0;
@@ -159,7 +161,6 @@ static int acpi_dev_pm_explicit_set(stru
*/
int acpi_device_set_power(struct acpi_device *device, int state)
{
- struct acpi_device *parent = acpi_dev_parent(device);
int target_state = state;
int result = 0;
@@ -192,13 +193,17 @@ int acpi_device_set_power(struct acpi_de
return -ENODEV;
}
- if (!device->power.flags.ignore_parent && parent &&
- state < parent->power.state) {
- acpi_handle_debug(device->handle,
- "Cannot transition to %s for parent in %s\n",
- acpi_power_state_string(state),
- acpi_power_state_string(parent->power.state));
- return -ENODEV;
+ if (!device->power.flags.ignore_parent) {
+ struct acpi_device *parent;
+
+ parent = acpi_dev_parent(device);
+ if (parent && state < parent->power.state) {
+ acpi_handle_debug(device->handle,
+ "Cannot transition to %s for parent in %s\n",
+ acpi_power_state_string(state),
+ acpi_power_state_string(parent->power.state));
+ return -ENODEV;
+ }
}
/*
