Use memory_limit (in ini) to increase the memory limit. This is not a bug.

or don't pass around whole files in strings which allocates memory often two or even three times

$h = finfo_open();
$mime_type = finfo_file($h, $path, FILEINFO_MIME_TYPE);
finfo_close($h);

@anestis: How large is $buffer, and are its contents valid (not corrupted) for the file type?

@bugreports: Passing strings around does not allocate new memory because of copy-on-write.

@requinix@php.net: just over 17M (17318320 bytes).

@requinix@php.net: It's a pdf file. Seems legit. The reader (foxit) opens it just fine.

This sounds similar to bug #78987. In any case, this is a bug in upstream libmagic, it needs to be reported and fixed there before we can do anything about it.

The error is produced when I use the following sequence:
1) read the data from a temp file into a buffer
2) call finfo_buffer to get the mimetype
3) parse the buffer

The error is not produced and everything works fine if the sequence is modified as follows:
1) call finfo_file on temp file to get the mimetype
2) read the data from the same temp file into a buffer
3) parse the buffer

I've created two scripts illustrating the problem with finfo_buffer:

Memory usage of finfo_file: https://3v4l.org/M3YLG
Memory usage of finfo_buffer: https://3v4l.org/LNNoV

On a 16M file, finfo_file uses 20M memory. finfo_buffer, however, uses 244M!

> In any case, this is a bug in upstream libmagic, it needs to be
> reported and fixed there before we can do anything about it.

Has anybody reported that upstream[1]?

[1] <http://darwinsys.com/file/>

No feedback was provided. The bug is being suspended because
we assume that you are no longer experiencing the problem.
If this is not the case and you are able to provide the
information that was requested earlier, please do so and
change the status of the bug back to "Re-Opened". Thank you.