0000234: Memory problems running finfo::buffer with PHP_CLI

ID	Project	Category	View Status	Date Submitted	Last Update

0000234	file	General	public	2021-02-03 12:13	2021-02-05 21:34

Reporter	halaei	Assigned To	christos
Priority	normal	Severity	major	Reproducibility	have not tried
Status	resolved	Resolution	fixed
Product Version	5.38
Fixed in Version	5.40

Summary	0000234: Memory problems running finfo::buffer with PHP_CLI
Description	PHP internally uses libmagic for getting information about files. This sample php code consumes 483 MB of RAM for detecting mimetype of a 48 MB MP3 file using php7.4 but it uses only 56 MB with php7.2. $finfo = new finfo(FILEINFO_MIME_TYPE, ''); $contents = file_get_contents('file.mp3'); echo($finfo->buffer($contents)); The bug is reported to php as well. They say it should be reported to libmagic. See https://bugs.php.net/bug.php?id=79263 The PHP bug is over 1 year old. I reported the bug here as well: https://bugs.launchpad.net/ubuntu/+bug/1914401 .Maybe it wasn't the right place
Steps To Reproduce	Having a large file.mp3 file. Run the following using php 7.4: <?php $finfo = new finfo(FILEINFO_MIME_TYPE, ''); $contents = file_get_contents('file.mp3'); echo($finfo->buffer($contents)); echo(memory_get_peak_usage(true)/1024/1024);
Tags	No tags attached.

Date Modified	Username	Field	Change
2021-02-03 12:13	halaei	New Issue
2021-02-05 21:34	christos	Assigned To	=> christos
2021-02-05 21:34	christos	Status	new => assigned
2021-02-05 21:34	christos	Status	assigned => resolved
2021-02-05 21:34	christos	Resolution	open => fixed
2021-02-05 21:34	christos	Fixed in Version	=> 5.40
2021-02-05 21:34	christos	Note Added: 0003533

christos 2021-02-05 21:34 manager ~0003533	file_buffer(3) passed the full size of the buffer to the encoding determination function. If the file was too large, we ended up allocating (2 * size + 4 * size) buffers to scan for encoding. Now we limit size to 64K.