From cf860be639d86ed77af179c925085ae0721ae602 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 24 Jan 2013 12:49:49 +0100 Subject: [PATCH] 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 Acked-by: Greg Kroah-Hartman --- drivers/acpi/internal.h | 5 +++-- drivers/acpi/power.c | 3 ++- drivers/acpi/scan.c | 20 +++++++++++++++----- 3 files changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 1f004f35bc67..c5a61cd6c1a5 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -40,10 +40,11 @@ static inline void acpi_debugfs_init(void) { return; } #define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \ ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING) -int acpi_device_register(struct acpi_device *device, - void (*release)(struct device *)); +int acpi_device_add(struct acpi_device *device, + void (*release)(struct device *)); void acpi_init_device_object(struct acpi_device *device, acpi_handle handle, int type, unsigned long long sta); +void acpi_device_add_finalize(struct acpi_device *device); void acpi_free_ids(struct acpi_device *device); /* -------------------------------------------------------------------------- diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 6db261c237d4..3f16dd4db23e 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -721,13 +721,14 @@ int acpi_add_power_resource(acpi_handle handle) 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: diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 1fc57a349a3c..8b3b18846c8c 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -634,8 +634,8 @@ struct bus_type acpi_bus_type = { .uevent = acpi_device_uevent, }; -int acpi_device_register(struct acpi_device *device, - void (*release)(struct device *)) +int acpi_device_add(struct acpi_device *device, + void (*release)(struct device *)) { int result; struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id; @@ -705,7 +705,7 @@ int acpi_device_register(struct acpi_device *device, device->dev.parent = &device->parent->dev; device->dev.bus = &acpi_bus_type; device->dev.release = release; - result = device_register(&device->dev); + result = device_add(&device->dev); if (result) { dev_err(&device->dev, "Error registering device\n"); goto err; @@ -744,12 +744,13 @@ static void acpi_device_unregister(struct acpi_device *device) acpi_power_add_remove_device(device, false); acpi_device_remove_files(device); - device_unregister(&device->dev); + device_del(&device->dev); /* * Drop the reference counts of all power resources the device depends * on and turn off the ones that have no more references. */ acpi_power_transition(device, ACPI_STATE_D3_COLD); + put_device(&device->dev); } /* -------------------------------------------------------------------------- @@ -1391,6 +1392,14 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle, acpi_device_get_busid(device); acpi_device_set_id(device); acpi_bus_get_flags(device); + device_initialize(&device->dev); + dev_set_uevent_suppress(&device->dev, true); +} + +void acpi_device_add_finalize(struct acpi_device *device) +{ + dev_set_uevent_suppress(&device->dev, false); + kobject_uevent(&device->dev.kobj, KOBJ_ADD); } static int acpi_add_single_object(struct acpi_device **child, @@ -1412,13 +1421,14 @@ static int acpi_add_single_object(struct acpi_device **child, acpi_bus_get_wakeup_device_flags(device); device->flags.match_driver = match_driver; - result = acpi_device_register(device, acpi_device_release); + result = acpi_device_add(device, acpi_device_release); if (result) { acpi_device_release(&device->dev); return result; } acpi_power_add_remove_device(device, true); + acpi_device_add_finalize(device); acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n", dev_name(&device->dev), (char *) buffer.pointer, -- 2.20.1