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integer overflow in session.c:1353 #16290
Description
Description
The following code:
<?php
session_set_cookie_params(PHP_INT_MAX, '/', null, false, true);
session_start();
?>Resulted in this output:
/home/dan/php-8.3.9/ext/session/session.c:1353:5: runtime error: signed integer overflow: 1728342208 + 9223372036854775807 cannot be represented in type 'long int'
Also, not tested with 8.3.12, yet.
PHP Version
8.3.9
Operating System
No response
Reacted by Marcus Xavier
Activity
MarcusXavierr commentedon Oct 8, 2024
I've tested it on a docker container with PHP 8.3.9 and went fine
I've also tested on my machine with PHP 8.2.15 and also didn't had any problem
Did you make any steps besides running this code?
MarcusXavierr commentedon Oct 8, 2024
Maybe the error occurs because the
PS(cookie_lifetime)is already the max positive size of long.But why does this overflow doesn't break anything on my machine?
And if the overflow is the problem, and the user can set cookie_lifetime to the max long int value, what are our options? Turning
tinto unsigned long?Test the possible overflow before assigning
t, and treating the overflow case with theLONG_MAXvalue fromlimits.h?cmb69 commentedon Oct 8, 2024
That overflow is undefined behavior; it may not necessarily cause issues, but should be fixed nonetheless. To reliably detect it, you either need to debug manually, or to employ something like UBSan.