This might be related to commit d6e81f0[1].  Johannes, could you
have a look at this issue please?

[1] <http://git.php.net/?p=php-src.git;a=commit;h=d6e81f0bfd0cb90586dd83d4fd47a4302605261a>

ping

the same with current 7.2 GIT

so now we have a master where opcache crashes and a 7.2 tree which still says it's 7.2.7-dev while the changelog has entries for 7.2.8 crahsing with mysqlnd

gdb don't really help even with a debug build, the only stacktrace i get is from systemd when running as oneshot-service

[root@testserver:~]$ systemctl start contentlounge-cleanup.service
[root@testserver:~]$ cat messages
Jun 12 19:12:34 testserver php[518756]: free(): invalid pointer
Jun 12 19:12:34 testserver systemd[1]: Started Process Core Dump (PID 518763/UID 0).
Jun 12 19:12:34 testserver systemd-coredump[518764]: Process 518762 (php) of user 4500 dumped core.

Stack trace of thread 518762:
#0  0x00007f8f519ba660 raise (libc.so.6)
#1  0x00007f8f519bbc41 abort (libc.so.6)
#2  0x00007f8f519fcf17 __libc_message (libc.so.6)
#3  0x00007f8f51a0321a malloc_printerr (libc.so.6)
#4  0x00007f8f51a04d5c _int_free (libc.so.6)
#5  0x00007f8f44156249 _mysqlnd_pefree (mysqlnd.so)
#6  0x00007f8f441451fb mysqlnd_mysqlnd_conn_data_free_contents_pub (mysqlnd.so)
#7  0x00007f8f441455da mysqlnd_mysqlnd_conn_data_dtor_priv (mysqlnd.so)
#8  0x00007f8f4414ca82 mysqlnd_mysqlnd_conn_data_free_reference_priv (mysqlnd.so)
#9  0x00007f8f441516cc mysqlnd_mysqlnd_conn_dtor_priv (mysqlnd.so)
#10 0x00007f8f44151b5d mysqlnd_mysqlnd_conn_close_pub (mysqlnd.so)
#11 0x00007f8f43f18175 php_mysqli_close (mysqli.so)
#12 0x00007f8f43f1215a mysqli_link_free_storage (mysqli.so)
#13 0x00005614f98cf3e2 zend_objects_store_free_object_storage (php)
#14 0x00005614f9863dc7 shutdown_executor (php)
#15 0x00005614f987e807 zend_deactivate (php)
#16 0x00005614f97ebb17 php_request_shutdown (php)
#17 0x00005614f9969851 do_cli (php)
#18 0x00005614f9969f2c main (php)
#19 0x00007f8f519a6f2a __libc_start_main (libc.so.6)
#20 0x00005614f9653cea _start (php)

[wwwcron@testserver:~]$ /usr/bin/php /Volumes/dune/updateservice/distribute/call_cronjob.php cleanup.php
free(): invalid pointer
[wwwcron@testserver:~]$ gdb --args /usr/bin/php /Volumes/dune/updateservice/distribute/call_cronjob.php cleanup.php
GNU gdb (GDB) Fedora 8.0.1-36.fc27
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/bin/php...done.
(gdb) run
Starting program: /usr/bin/php /Volumes/dune/updateservice/distribute/call_cronjob.php cleanup.php
Missing separate debuginfos, use: dnf debuginfo-install php-cli-7.2.8-3.0.fc27.20180612.1853.rh.sandybridge.x86_64
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Detaching after fork from child process 518628.
Detaching after fork from child process 518629.
Detaching after fork from child process 518630.
Detaching after fork from child process 518631.
free(): invalid pointer
Detaching after fork from child process 518634.
[Inferior 1 (process 518624) exited normally]
(gdb) bt
No stack.

This issue should be fixed by https://github.com/php/php-src/commit/11507c0e1bfa17a96480f3648397f6975c31551e. Can you please verify that current 7.2 HEAD resolves this problem for you?

confirmed - thanks!

p.s.: the bugtracker is terrible slow currently and ends in repeated timeouts

Thanks for checking! Assigning this to krakjoe to make sure this fix is cherry-picked into the 7.1 release (or else the original change reverted).

PHP 7.1 doesn't appear to be affected by this, but has reached
it's end of life anyway, so I'm closing this ticket.