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perl-5.45.1
⭐ Starred 2013 / XS::Typemap
Security Advisories (1)
CVE-2026-15534 (2026-08-09)

Perl versions through 5.45.1 have out-of-bounds heap reads and writes during regular expression matching via an undersized superlinear cache in S_regmatch. The regex engine's superlinear cache holds one bit per subject position for each participating WHILEM node, so the bit count is the subject length plus one times the number of nodes. Nothing checks that product for positive overflow of the signed 32-bit count: a 286331153 byte subject matched against a pattern with 15 participating nodes stores the count as 14, leaving a two byte cache. The cache is then indexed from the real match position and node number, so reads go past the end of the allocation, and on failure CACHEsayNO sets a bit past it. A caller that matches an attacker controlled subject of this size against a pattern of this shape can crash the process or corrupt heap memory.

NAME

XS::Typemap - module to test the XS typemaps distributed with perl

SYNOPSIS

use XS::Typemap;

$output = T_IV( $input );
$output = T_PV( $input );
@output = T_ARRAY( @input );

DESCRIPTION

This module is used to test that the XS typemaps distributed with perl are working as advertised. A function is available for each typemap definition (eventually). In general each function takes a variable, processes it through the OUTPUT typemap and then returns it using the INPUT typemap.

A test script can then compare the input and output to make sure they are the expected values. When only an input or output function is provided the function will be named after the typemap entry and have either '_IN' or '_OUT' appended.

All the functions are exported. There is no reason not to do this since the entire purpose is for testing Perl. Namespace pollution will be limited to the test script.

NOTES

This module is for testing only and should not normally be installed.

AUTHOR

Tim Jenness <t.jenness@jach.hawaii.edu>

Copyright (C) 2001 Tim Jenness All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.