mod_cluster causes httpd seg faults when JBoss connects

Issue

• JBoss is failing to connect to httpd through mod_cluster:

ERROR [org.jboss.modcluster.mcmp.impl.DefaultMCMPHandler] (ContainerBackgroundProcessor[StandardEngine[jboss.web]]) Error [null: null: {4}] sending command STATUS to proxy 127.0.0.1:6666, configuration will be reset

• httpd logs repeated seg faults during these failed STATUS MCMP requests:

[notice] child pid 2018 exit signal Segmentation fault (11)

• A backtrace of a generated core dump from this seg fault shows the crash occurs in some strcmp calls made from mod_cluster:

#0  0x00007f481a02a2c4 in __strcmp_sse2 () from /lib64/libc.so.6
#1  0x00007f4817ed18d3 in ?? ()
   from /jboss/jboss-ews-2.0/httpd/modules/mod_proxy_cluster.so
#2  0x00007f4817ed4c9b in ?? ()
   from /jboss/jboss-ews-2.0/httpd/modules/mod_proxy_cluster.so
#3  0x00007f48180e3607 in ?? ()
   from /jboss/jboss-ews-2.0/httpd/modules/mod_manager.so
#4  0x00007f48180e38c4 in ?? ()
   from /jboss/jboss-ews-2.0/httpd/modules/mod_manager.so
#5  0x00007f48180e6bc1 in ?? ()
   from /jboss/jboss-ews-2.0/httpd/modules/mod_manager.so
#6  0x00007f481ba99f70 in ap_run_handler (r=0x7f481d883f88)
    at /builddir/build/BUILD/httpd-2.2.22/server/config.c:158
#7  0x00007f481ba9d80e in ap_invoke_handler (r=0x7f481d883f88)
    at /builddir/build/BUILD/httpd-2.2.22/server/config.c:376
#8  0x00007f481baa8f80 in ap_process_request (r=0x7f481d883f88)
    at /builddir/build/BUILD/httpd-2.2.22/modules/http/http_request.c:282
#9  0x00007f481baa5d48 in ap_process_http_connection (c=0x7f481d878118)
    at /builddir/build/BUILD/httpd-2.2.22/modules/http/http_core.c:190
#10 0x00007f481baa1a58 in ap_run_process_connection (c=0x7f481d878118)
    at /builddir/build/BUILD/httpd-2.2.22/server/connection.c:43
#11 0x00007f481baadef7 in child_main (child_num_arg=<value optimized out>)
    at /builddir/build/BUILD/httpd-2.2.22/server/mpm/prefork/prefork.c:667