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Commit 2d559513 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI / ACPICA: Avoid crashing if _PRW is defined for the root object 



Some ACPI BIOSes define _PRW for the root object which causes
acpi_setup_gpe_for_wake() to crash when trying to dereference the
bogus device_node pointer.  Avoid the crash by checking if
wake_device is not the root object before attempting to set up the
"implicit notify" mechanism for it.

The problem was introduced by commit bba63a29
(ACPICA: Implicit notify support) that added the wake_device argument
to acpi_setup_gpe_for_wake().

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 100b33c8

drivers/acpi/acpica/evxfgpe.c

+26 −23
Original line number Diff line number Diff line
@@ -212,37 +212,40 @@ acpi_setup_gpe_for_wake(acpi_handle wake_device, 
		return_ACPI_STATUS(AE_BAD_PARAMETER);

	}



	/* Validate wake_device is of type Device */



	device_node = ACPI_CAST_PTR(struct acpi_namespace_node, wake_device);

	if (device_node->type != ACPI_TYPE_DEVICE) {

		return_ACPI_STATUS(AE_BAD_PARAMETER);

	}



	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);



	/* Ensure that we have a valid GPE number */



	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);

	if (gpe_event_info) {

	if (!gpe_event_info) {

		goto unlock_and_exit;

	}



	/*

	 * If there is no method or handler for this GPE, then the

	 * wake_device will be notified whenever this GPE fires (aka

	 * "implicit notify") Note: The GPE is assumed to be

	 * level-triggered (for windows compatibility).

	 */

		if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==

		    ACPI_GPE_DISPATCH_NONE) {

			gpe_event_info->flags =

			    (ACPI_GPE_DISPATCH_NOTIFY |

	if (((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==

	      ACPI_GPE_DISPATCH_NONE) && (wake_device != ACPI_ROOT_OBJECT)) {



		/* Validate wake_device is of type Device */



		device_node = ACPI_CAST_PTR(struct acpi_namespace_node,

					    wake_device);

		if (device_node->type != ACPI_TYPE_DEVICE) {

			goto unlock_and_exit;

		}

		gpe_event_info->flags = (ACPI_GPE_DISPATCH_NOTIFY |

					 ACPI_GPE_LEVEL_TRIGGERED);

		gpe_event_info->dispatch.device_node = device_node;

	}



	gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;

	status = AE_OK;

	}



 unlock_and_exit:

	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

	return_ACPI_STATUS(status);

}