ACPI / scan: Prevent device add uevents from racing with user space
ACPI core adds sysfs device files after the given devices have been
registered with device_register(), which is not appropriate, because
it may lead to race conditions with user space tools using those
files.
Fix the problem by delaying the KOBJ_ADD uevent for ACPI devices
until after all of the devices' sysfs files have been created.
This also fixes a use-after-free in acpi_device_unregister().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 6db261c..3f16dd4 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -721,13 +721,14 @@
acpi_device_bid(device), state ? "on" : "off");
device->flags.match_driver = true;
- result = acpi_device_register(device, acpi_release_power_resource);
+ result = acpi_device_add(device, acpi_release_power_resource);
if (result)
goto err;
mutex_lock(&power_resource_list_lock);
list_add(&resource->list_node, &acpi_power_resource_list);
mutex_unlock(&power_resource_list_lock);
+ acpi_device_add_finalize(device);
return 0;
err: