Description of problem:

Apache httpd in RHEL7 configured with worker/event mpm segfaults after receiving multiple SIGUSR1. 2.4.6-67.el7_4.6.x86_64 also has problems. 


Version-Release number of selected component (if applicable):

* RHEL7 Latest 2.4.6-67.el7_4.6.x86_64

How reproducible:

Near 100% with worker or event

Steps to Reproduce:
  1. Install httpd
  2. Ensure using worker or event
     (E.g.: sed -i -e '/^Load/s/^/#/' -e '/#Load.*event/s/^#//' /etc/httpd/conf.modules.d/00-mpm.conf)
  3. systemctl restart httpd
  4. Repeat "# kill -USR1 `cat /var/run/httpd/httpd.pid`; kill -USR1 `cat /var/run/httpd/httpd.pid`"

Actual results:

 [Fri Dec 15 10:39:29.964033 2017] [mpm_worker:notice] [pid 20084:tid 
140575944685696] AH00297: SIGUSR1 received.  Doing graceful restart
 [Fri Dec 15 10:39:30.084318 2017] [core:notice] [pid 20084] AH00060: 
seg fault or similar nasty error detected in the parent process

Expected results:

 httpd shouldn't segfault. With prefork, it doesn't

Additional info:

 The problem (httpd with worker/event mpm segfaults after multiple successive graceful reloads) was fixed in 2.4.6-53.el7 (Development Version)

- Apache httpd with worker/event mpm segfaults after multiple 
　　successive graceful reloads triggered by logrotate
      https://access.redhat.com/solutions/2626601

* Tue Mar 07 2017 Luboš Uhliarik <luhliari> - 2.4.6-53
- Resolves: #1376835 - httpd with worker/event mpm segfaults after multiple
  successive graceful reloads

httpd-2.4.6-mpm-segfault.patch
============
--- a/server/mpm/event/event.c
+++ a/server/mpm/event/event.c
@@ -2735,6 +2735,7 @@ static int event_run(apr_pool_t * _pconf, apr_pool_t * plog, server_rec * s)

     /* we've been told to restart */
     apr_signal(SIGHUP, SIG_IGN);
+    apr_signal(AP_SIG_GRACEFUL, SIG_IGN);
     if (one_process) {
         /* not worth thinking about */
============

httpd in RHEL7 configured with worker/event mpm segfaults after receiving
multiple SIGUSR1. (logrotate.conf example: size 1G and daily)
2.4.6-67.el7_4.6.x86_64 also has problems. 

I think that the aforementioned patch is not sufficient and need to add accurate exclusion control.