Re: [PATCH] ACPI / PM: Fix error code path for power resources initialization

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Tue, Jun 18, 2013 at 12:37:45AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Commit 781d737 (ACPI: Drop power resources driver) introduced a
> bug in the power resources initialization error code path causing
> a NULL pointer to be referenced in acpi_release_power_resource()
> if there's an error triggering a jump to the 'err' label in
> acpi_add_power_resource().  This happens because the list_node
> field of struct acpi_power_resource has not been initialized yet
> at this point and doing a list_del() on it is a bad idea.
> 
> To prevent this problem from occuring, initialize the list_node
> field of struct acpi_power_resource upfront.
> 
> Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Cc: 3.9+ <stable@vger.kernel.org>
> ---
>  drivers/acpi/power.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> Index: linux-pm/drivers/acpi/power.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/power.c
> +++ linux-pm/drivers/acpi/power.c
> @@ -882,6 +882,7 @@ int acpi_add_power_resource(acpi_handle
>  				ACPI_STA_DEFAULT);
>  	mutex_init(&resource->resource_lock);
>  	INIT_LIST_HEAD(&resource->dependent);
> +	INIT_LIST_HEAD(&resource->list_node);
>  	resource->name = device->pnp.bus_id;
>  	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
>  	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);