CakePHPのキャッシュファイルのパーミッションエラーの対処法

Warning: SplFileInfo::openFile(/www/app/tmp/cache/persistent/cake_core_cake_console_) [splfileinfo.openfile]: failed to open stream: Permission denied in /www/lib/Cake/Cache/Engine/FileEngine.php

'mask' => 0666

Cache::config('_cake_core_', array(
    'engine' => $engine,
    'prefix' => $prefix . 'cake_core_',
    'path' => CACHE . 'persistent' . DS,
    'serialize' => ($engine === 'File'),
    'duration' => $duration,
    'mask' => 0666,
));
Cache::config('_cake_model_', array(
    'engine' => $engine,
    'prefix' => $prefix . 'cake_model_',
    'path' => CACHE . 'models' . DS,
    'serialize' => ($engine === 'File'),
    'duration' => $duration,
    'mask' => 0666,
));