Description:
------------
Hi,

I'm running Apache 2.4.41 on CentOS 6.4 server.

There was a problem (memory corruption),
when graceful reloading the httpd service many times.

The version of each app is as follows:
 - httpd-2.4.41
 - apr-1.5.2
 - apr-util-1.5.4
 - php-7.3.4

The following steps will cause the problem.

 # cat /opt/httpd/htdocs/index.php
 ------
 <?php
 phpinfo();
 ?>
 ------

 # /etc/init.d/httpd start
 Starting httpd:                                            [  OK  ]


Display phpinfo() in your browser and check that it is working.
 http://localhost/index.php


Now, when I run the following script, an error occurs (about 1023 times).

 # for i in $(seq 1030) ; do echo $i; /opt/httpd/bin/httpd -k graceful;  done

 # less /opt/httpd/log/error_log
 ・・・・
 [XXX XXX XX 16:05:23.261688 2020] [mpm_prefork:notice] [pid 2875] AH00171: Graceful restart requested, doing restart
 *** glibc detected *** /opt/httpd/bin/httpd: malloc(): memory corruption: 0x00000000021a4010 ***
 *** glibc detected *** /opt/httpd/bin/httpd: malloc(): memory corruption: 0x00000000021a4010 ***



This bug occurs when loading the libphp7.so module.
Different libphp7.so versions have the same result.
But that doesn't happen with the libphp5.so module.
It occurs on CentOS 7 as well as CentOS 6.

Thanks,
Regards.