PCOV causes segmentation fault during memory overflow.

[Porthorian]

Description

The following code:

<?php declare(strict_types=1);

////
// Execute the bug
////
main();


////
// Minimum Viable Bug
////

interface SessionCookieInterface
{
}

interface SessionRepositoryInterface
{
}

class SessionFactory
{
	public function createSession(string $session_name, ?SessionCookieInterface $cookie = null, ?SessionRepositoryInterface $repo = null) : SessionInterface
	{
		if ($cookie === null)
		{
			$cookie = self::generateDefaultSession();
		}

		return (new Session())
			->withName($session_name)
			->withCookieParams($cookie);
	}

	public static function generateDefaultSession() : SessionInterface
	{
		return (new SessionFactory())->createSession('test1234');
	}
}

class Session
{
	private string $name = 'SID';
	private SessionCookieInterface $cookie;

	public function withName(string $session_name) : self
	{
		$new = clone $this;
		$new->name = $session_name;

		return $new;
	}

	public function withCookieParams(SessionCookieInterface $cookie) : self
	{
		$new = clone $this;
		$new->cookie = $cookie;

		return $new;
	}
}

function main()
{
	$session = (new SessionFactory())->createSession('test1234');
}

Resulted in this output:

Output of script

root@175dab3f7cb7:/home/app/src/Session# php test_segmentation.php
Segmentation fault (core dumped)
root@175dab3f7cb7:/home/app/src/Session# 

===========Core Dump information=========
[vmarone@vinnielab: ~/projects/aiur/aiur-api]$ gdb /usr/bin/php /tmp/coredump-php.741983
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Reading symbols from /usr/bin/php...
(No debugging symbols found in /usr/bin/php)
[New LWP 741983]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
Core was generated by `php src/Session/test_segmentation.php'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007f2bc2a796bb in php_pcov_execute_ex () from /usr/lib/php/modules/pcov.so
(gdb) q
[vmarone@vinnielab: ~/projects/aiur/aiur-api]$

=========LOGS========

aiur_php    | [27-Sep-2022 19:43:08] WARNING: [pool www] child 8 exited on signal 11 (SIGSEGV - core dumped) after 3.834072 seconds from start
aiur_php    | [27-Sep-2022 19:43:08] NOTICE: [pool www] child 10 started
aiur_php    | [27-Sep-2022 19:43:38] WARNING: [pool www] child 9 exited on signal 11 (SIGSEGV - core dumped) after 33.987749 seconds from start
aiur_php    | [27-Sep-2022 19:43:38] NOTICE: [pool www] child 11 started
aiur_php    | 172.31.0.5 -  27/Sep/2022:19:44:01 +0000 "POST /index.php" 200
aiur_php    | [27-Sep-2022 19:44:44] ALERT: oops, unknown child (22) exited with code 0. Please open a bug report (https://github.com/php/php-src/issues).
aiur_php    | [27-Sep-2022 19:44:56] WARNING: [pool www] child 11 exited on signal 11 (SIGSEGV - core dumped) after 78.615515 seconds from start
aiur_php    | [27-Sep-2022 19:44:56] NOTICE: [pool www] child 27 started
aiur_php    | [27-Sep-2022 19:45:41] WARNING: [pool www] child 10 exited on signal 11 (SIGSEGV - core dumped) after 153.733791 seconds from start
aiur_php    | [27-Sep-2022 19:45:41] NOTICE: [pool www] child 28 started
aiur_php    | [27-Sep-2022 19:45:49] WARNING: [pool www] child 27 exited on signal 11 (SIGSEGV - core dumped) after 52.722584 seconds from start
aiur_php    | [27-Sep-2022 19:45:49] NOTICE: [pool www] child 29 started
aiur_php    | [27-Sep-2022 19:45:59] WARNING: [pool www] child 28 exited on signal 11 (SIGSEGV - core dumped) after 17.311002 seconds from start
aiur_php    | [27-Sep-2022 19:45:59] NOTICE: [pool www] child 30 started
aiur_php    | [27-Sep-2022 19:47:00] ALERT: oops, unknown child (42) exited with code 0. Please open a bug report (https://github.com/php/php-src/issues).
aiur_php    | [27-Sep-2022 19:47:17] ALERT: oops, unknown child (57) exited with code 0. Please open a bug report (https://github.com/php/php-src/issues).
aiur_php    | [27-Sep-2022 19:48:19] ALERT: oops, unknown child (72) exited with code 0. Please open a bug report (https://github.com/php/php-src/issues).
aiur_php    | [27-Sep-2022 19:48:48] ALERT: oops, unknown child (87) exited with code 0. Please open a bug report (https://github.com/php/php-src/issues).

But I expected this output instead:

The expected output should of probably been some sort of fatal exception, not crash the entire php-fpm child.

Something like this.

[vmarone@vinnielab: ~/projects/aiur/aiur-api]$ php src/Session/test_segmentation.php
PHP Fatal error:  Allowed memory size of 134217728 bytes exhausted (tried to allocate 262144 bytes) in /home/vmarone/projects/aiur/aiur-api/src/Session/test_segmentation.php on line 37
[vmarone@vinnielab: ~/projects/aiur/aiur-api]$

PHP Version

8.1.9

Operating System

Linux 175dab3f7cb7 5.19.7-arch1-1 #1 SMP PREEMPT_DYNAMIC Mon, 05 Sep 2022 18:09:09 +0000 x86_64 GNU/Linux

[Porthorian]

The bug was originally opened up at php/php-src#9623