Memory exhausted (minimal script)

Question

This is something that has never happened to me before.

I receive Allowed memory size of X bytes exhausted but my script hardly uses any memory.

I created a small test script, with minimal code, and it still fails!

$ cat x.php
#!/usr/bin/env php
<?php

function ha($msg) {

}

ha("Hi");

$ ./x.php

Fatal error: Allowed memory size of 62914560 bytes exhausted (tried to allocate 1081028648 bytes) in x.php on line 4

Interestingly if I remove the $msg parameter of the function it does not emit a warning. As said, I never had this happen before. The php.ini is normal too.

System information:

$ php -v
PHP 5.6.19 (cli) (built: Jun 22 2016 20:13:44)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies

$ php -m
[PHP Modules]
bcmath
calendar
Core
ctype
date
dom
ereg
exif
filter
gd
hash
json
libxml
mbstring
openssl
pcntl
pcre
PDO
pdo_sqlite
posix
Reflection
session
shmop
SimpleXML
soap
sockets
SPL
sqlite3
standard
sysvmsg
sysvsem
sysvshm
tokenizer
xml
xmlreader
xmlwriter
zip
zlib

[Zend Modules]

$ df -h
Filesystem                Size      Used Available Use% Mounted on
ubi0:rootfs             362.9M    122.2M    240.7M  34% /
tmpfs                    40.0K         0     40.0K   0% /mnt/.splash
none                      1.0M    116.0K    908.0K  11% /dev
/dev/sda1                56.8G      5.4G     48.5G  10% /media/sda1
tmpfs                    50.0M     72.0K     49.9M   0% /var/volatile
tmpfs                   123.9M         0    123.9M   0% /dev/shm
tmpfs                    20.0M         0     20.0M   0% /media/ram

$ cat /proc/meminfo
MemTotal:         253712 kB
MemFree:          179720 kB

Answer 1

Wow I never thought that I would actually encounter something like this.

The reason this happened is because a bit (!!) got flipped in the binary.

I replaced the binary with a fresh one and it worked again.

Here's the difference of the two binaries: