请教ctf web 问题

Question

ctf web 问题

 <?php 
    highlight_file(__FILE__);
    error_reporting(0); 
    ini_set('open_basedir',"/var/www/html");
    $file=$_GET['f'];
    if(preg_match("/flag|secret|index/i",$file))
    {
      die("nononono");
    }
    include_once($file);
    $sec=$_GET['pop'];
    if(isset($sec))
    {
       unserialize($sec);
    }    
?>

我绕不过去，请帮帮忙

Answer 1

https://ask.csdn.net/questions/7493951?spm=1005.2026.3001.5635&utm_medium=distribute.pc_relevant_ask_down.none-task-ask-2~default~OPENSEARCH~Rate-1-7493951-ask-7779571.pc_feed_download_top3ask&depth_1-utm_source=distribute.pc_relevant_ask_down.none-task-ask-2~default~OPENSEARCH~Rate-1-7493951-ask-7779571.pc_feed_download_top3ask