Bug #73619 [Opn->Csd]: Crash or zend_mm_heap_corrupted error in opcache with OwnCloud 7 update

Edit report at https://bugs.php.net/bug.php?id=73619&edit=1 ID: 73619 User updated by: adamw at happyassassin dot net Reported by: adamw at happyassassin dot net Summary: Crash or zend_mm_heap_corrupted error in opcache with OwnCloud 7 update -Status: Open +Status: Closed Type: Bug Package: opcache Operating System: Fedora 20 PHP Version: 7.0.13 Block user comment: N Private report: N New Comment: I have absolutely no idea how this wound up as a dupe of https://bugs.php.net/bug.php?id=67687 , as I filed it with completely different content. Can only imagine it's some kind of bug to do with using the same password for both bugs. Previous Comments: ------------------------------------------------------------------------ [2016-11-28 21:14:46] adamw at happyassassin dot net Description: ------------ See downstream bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1398474 SELinux blocks web servers from what it calls 'execmem' actions by default; as I understand it, this means execution of writeable memory, which is considered a potential avenue for exploitation and not to be necessary for well-written code. With PHP 7.0.13's default configuration, where just-in-time compilation of PCREs is enabled, Fedora 25 systems see a flood of these 'execmem' denials. Disabling the PCRE JIT feature with pcre.jit=0 makes them go away. There is some more discussion of this at https://unix.stackexchange.com/questions/287831/how-to-work-out-why-apache-is-attempting-execmem , where several people traced this problem to the PCRE JIT code using gdb and backtraces are available. These seem to run through _pcre_jit_compile / pcre_study / pcre_get_compiled_regex_cache / php_do_pcre_match . ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=73619&edit=1