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

From: Mika Westerberg
Date: Wed Jun 19 2013 - 03:25:57 EST


On Tue, Jun 18, 2013 at 12:37:45AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxx>

Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Cc: 3.9+ <stable@xxxxxxxxxxxxxxx>
> ---
> 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);
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