php5-fpm crashed with SIGSEGV in ZEND_FETCH_DIM_R_SPEC_VAR_CONST_HANDLER()

[Lockal]

php5-fpm (nginx + unix sockets) crashes while doing a search in mediawiki. Not sure yet about php backtrace, but the one, provided by apport could be helpful.

ProblemType: Crash
DistroRelease: Ubuntu 13.10
Package: php5-fpm 5.5.3+dfsg-1ubuntu1
ProcVersionSignature: Ubuntu 3.11.0-5.10-generic 3.11.0
Uname: Linux 3.11.0-5-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.12.1-0ubuntu4
Architecture: amd64
Date: Sun Sep 15 01:54:50 2013
ExecutablePath: /usr/sbin/php5-fpm
InstallationDate: Installed on 2012-02-05 (587 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120201.1)
MarkForUpload: True
ProcCmdline: php-fpm:\ pool\ www
ProcEnviron:

SegvAnalysis:
 Segfault happened at: 0x771f4f: mov 0x0(%r13),%rsi
 PC (0x00771f4f) ok
 source "0x0(%r13)" (0x00000000) not located in a known VMA region (needed readable region)!
 destination "%rsi" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: php5
StacktraceTop:
 ?? ()
 execute_ex ()
 zend_execute_scripts ()
 php_execute_script ()
 main ()
Title: php5-fpm crashed with SIGSEGV in execute_ex()
UpgradeStatus: Upgraded to saucy on 2013-05-19 (118 days ago)
UserGroups:

[Apport retracing service (apport)]

StacktraceTop:
 ZEND_FETCH_DIM_R_SPEC_VAR_CONST_HANDLER (execute_data=0x7ffe20bec8d8) at /build/buildd/php5-5.5.3+dfsg/Zend/zend_vm_execute.h:14784
 execute_ex (execute_data=0x7ffe20bec8d8) at /build/buildd/php5-5.5.3+dfsg/Zend/zend_vm_execute.h:356
 zend_execute_scripts (type=type@entry=8, retval=retval@entry=0x0, file_count=file_count@entry=3) at /build/buildd/php5-5.5.3+dfsg/Zend/zend.c:1316
 php_execute_script (primary_file=primary_file@entry=0x7fff0651c210) at /build/buildd/php5-5.5.3+dfsg/main/main.c:2484
 main (argc=<optimized out>, argv=<optimized out>) at /build/buildd/php5-5.5.3+dfsg/sapi/fpm/fpm/fpm_main.c:1933

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sean (sean-q)]

This is caused by the "opcache" php module in conjunction with the "CACHE_ACCEL" setting in Mediawiki. If either $wgMainCacheType is set to CACHE_NONE or "opcache" php module is disabled Mediawiki search will no longer cause php exceptions, and function as expected.

For reference:

https://bugs.php.net/bug.php?id=65510