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Bug #78612 strtr leaks memory when integer keys are used and the subject string shorter
Submitted: 2019-09-30 12:27 UTC Modified: 2019-09-30 13:03 UTC
From: itsoft3g at gmail dot com Assigned: nikic (profile)
Status: Closed Package: Strings related
PHP Version: 7.3.10 OS: Ubuntu 18.04.2 LTS
Private report: No CVE-ID: None
 [2019-09-30 12:27 UTC] itsoft3g at gmail dot com
Description:
------------
Passing 2nd argument as an array to strtr() - replace substrings
Here array keys are integers.

Say an interger (7111222333000001) is the find item, consider it as string its length is 16.
Say the subject is Hello which length is 5.

In this case, strtr leaks memory.

However, when the subject is longer than the find item, there is no memory leak.
Also when the find is string there too no memory leak.

Test script:
---------------
$find_replace = array();
$_a = 7111222333000001;//find - consider as string it's length is 16
$_b = 5000001;

for($j=0;$j<10;$j++){	
	$find_replace[$_a + $j] = $_b + $j;
}

function test_strtr($subject, $find_replace){
	$memory_before = memory_get_usage();
	for($i=0;$i<50000;$i++){
		strtr($subject, $find_replace);
	}
	echo round( (memory_get_usage() - $memory_before) /(1024*1024), 4 ).' MB ';
}

test_strtr('Hello', $find_replace);//subject is shorter then find(length 5), memory leaks
test_strtr('Lorem ipsum dolor', $find_replace);//subject is lengthier then find(length 17), no memory leak


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AllCommentsChangesGit/SVN commitsRelated reports
 [2019-09-30 12:59 UTC] nikic@php.net
-Status: Open +Status: Verified
 [2019-09-30 13:03 UTC] nikic@php.net
-Assigned To: +Assigned To: nikic
 [2019-09-30 13:07 UTC] nikic@php.net
Automatic comment on behalf of nikita.ppv@gmail.com
Revision: http://git.php.net/?p=php-src.git;a=commit;h=6fcde56b0370125c32e6a7d198aff2afd01c35dc
Log: Fixed bug #78612
 [2019-09-30 13:07 UTC] nikic@php.net
-Status: Verified +Status: Closed
 
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