Apache crashing with seg fault on a graceful restart on Ubuntu 14.04
<p>One of the servers I manage runs <code>Ubuntu 14.04.5 LTS</code> with <code>Apache 2.4.7</code> and <code>PHP 7.0.11</code> , and uses <code>PHP's Zend OPcache v7.0.11</code>. It is noted that apache went down every time when we ran the <code>service apache2 graceful</code> (service apache2 reload) command. Apache error log showing the following.  </p>

<pre><code>[mpm_prefork:notice] [pid 9662] AH00171: Graceful restart requested, doing restart
*** Error in `/usr/sbin/apache2': corrupted double-linked list: 0x00007f9e1ae8a170 ***
[core:notice] [pid 9662] AH00060: seg fault or similar nasty error detected in the parent process   
</code></pre>

<p>Apache configuration</p>

<pre><code>#apachectl -V
Server version: Apache/2.4.7 (Ubuntu)
Server built:   Jul 15 2016 15:34:04 
Server's Module Magic Number: 20120211:27  
Server loaded:  APR 1.5.1-dev, APR-UTIL 1.5.3  
Compiled using: APR 1.5.1-dev, APR-UTIL 1.5.3  
Architecture:   64-bit  
Server MPM:     prefork  
  threaded:     no  
    forked:     yes (variable process count)  
Server compiled with....  
 -D APR_HAS_SENDFILE  
 -D APR_HAS_MMAP  
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)  
 -D APR_USE_SYSVSEM_SERIALIZE  
 -D APR_USE_PTHREAD_SERIALIZE  
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT  
 -D APR_HAS_OTHER_CHILD  
 -D AP_HAVE_RELIABLE_PIPED_LOGS  
 -D DYNAMIC_MODULE_LIMIT=256  
 -D HTTPD_ROOT="/etc/apache2"  
 -D SUEXEC_BIN="/usr/lib/apache2/suexec"  
 -D DEFAULT_PIDLOG="/var/run/apache2.pid"  
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"  
 -D DEFAULT_ERRORLOG="logs/error_log"  
 -D AP_TYPES_CONFIG_FILE="mime.types"  
 -D SERVER_CONFIG_FILE="apache2.conf"
</code></pre>

<p>After some amount of searching on the Internet, the only thing I could come up with that there were some Apache modules might be causing this issue. One of the posts indicated that this particular message is also a symptom for lots of other memory-type bugs in Apache. <strong>After disabling the php7.0</strong> module the issue resolved  </p>

<p>However anyone can help me to fix this issue without disabling the apache php module ?</p>

<p>Thanks in advance  </p>