USB: cdc-wdm: remove from device list on disconnect

Prevents dereferencing an invalid struct usb_interface
pointer.

Always delete entry from device list whether or not the
rest of the device state cleanup is postponed. The device
list uses desc->intf as key, and wdm_open will dereference
this key while searching for a matching device.  A device
should not appear in the list unless probe() has succeeded
and disconnect() has not finished.

Cc: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bjørn Mork 2012-05-09 13:53:23 +02:00 коммит произвёл Greg Kroah-Hartman
Родитель 6b0b79d388
Коммит 6286d85e8e
1 изменённых файлов: 9 добавлений и 3 удалений

Просмотреть файл

@ -309,9 +309,6 @@ static void free_urbs(struct wdm_device *desc)
static void cleanup(struct wdm_device *desc)
{
spin_lock(&wdm_device_list_lock);
list_del(&desc->device_list);
spin_unlock(&wdm_device_list_lock);
kfree(desc->sbuf);
kfree(desc->inbuf);
kfree(desc->orq);
@ -782,6 +779,9 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
out:
return rv;
err:
spin_lock(&wdm_device_list_lock);
list_del(&desc->device_list);
spin_unlock(&wdm_device_list_lock);
cleanup(desc);
return rv;
}
@ -907,6 +907,12 @@ static void wdm_disconnect(struct usb_interface *intf)
cancel_work_sync(&desc->rxwork);
mutex_unlock(&desc->wlock);
mutex_unlock(&desc->rlock);
/* the desc->intf pointer used as list key is now invalid */
spin_lock(&wdm_device_list_lock);
list_del(&desc->device_list);
spin_unlock(&wdm_device_list_lock);
if (!desc->count)
cleanup(desc);
else