/ 
perl-5.42.2
⭐ Starred 2013 / MakeMaker::Test::Utils
Security Advisories (4)
CVE-2026-13221 (2026-07-13)

Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk. When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error. A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.

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.

CVE-2026-57432 (2026-07-13)

Perl versions through 5.43.10 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves with a signed length comparison that passes when the length is negative, advancing the buffer pointer out of bounds. A template derived from untrusted input can read heap memory past the buffer and return it to the caller.

CVE-2026-8376 (2026-05-25)

Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer. A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.

NAME

MakeMaker::Test::Utils - Utility routines for testing MakeMaker

SYNOPSIS

use MakeMaker::Test::Utils;

my $perl     = which_perl;
perl_lib;

my $makefile      = makefile_name;
my $makefile_back = makefile_backup;

my $make          = make;
my $make_run      = make_run;
make_macro($make, $targ, %macros);

my $mtime         = calibrate_mtime;

my $out           = run($cmd);

my $have_compiler = have_compiler();

my $text          = slurp($filename);

DESCRIPTION

A consolidation of little utility functions used through out the MakeMaker test suite.

Functions

The following are exported by default.

which_perl
my $perl = which_perl;

Returns a path to perl which is safe to use in a command line, no matter where you chdir to.

perl_lib
perl_lib;

Sets up environment variables so perl can find its libraries. Run this before changing directories.

makefile_name
my $makefile = makefile_name;

MakeMaker doesn't always generate 'Makefile'. It returns what it should generate.

makefile_backup
my $makefile_old = makefile_backup;

Returns the name MakeMaker will use for a backup of the current Makefile.

make
my $make = make;

Returns a good guess at the make to run.

make_run
my $make_run = make_run;

Returns the make to run as with make() plus any necessary switches.

make_macro
my $make_cmd = make_macro($make, $target, %macros);

Returns the command necessary to run $make on the given $target using the given %macros.

my $make_test_verbose = make_macro(make_run(), 'test', 
                                   TEST_VERBOSE => 1);

This is important because VMS's make utilities have a completely different calling convention than Unix or Windows.

%macros is actually a list of tuples, so the order will be preserved.

calibrate_mtime
my $mtime = calibrate_mtime;

When building on NFS, file modification times can often lose touch with reality. This returns the mtime of a file which has just been touched.

run
my $out = run($command);
my @out = run($command);

Runs the given $command as an external program returning at least STDOUT as $out. If possible it will return STDOUT and STDERR combined as you would expect to see on a screen.

run_ok
my @out = run_ok($cmd);

Like run() but it tests that the result exited normally.

The output from run() will be used as a diagnostic if it fails.

have_compiler
$have_compiler = have_compiler;

Returns true if there is a compiler available for XS builds.

slurp
$contents = slurp($filename);

Returns the $contents of $filename.

Will die if $filename cannot be opened.

can_run

can_run takes only one argument: the name of a binary you wish to locate. can_run works much like the unix binary which or the bash command type, which scans through your path, looking for the requested binary.

Unlike which and type, this function is platform independent and will also work on, for example, Win32.

If called in a scalar context it will return the full path to the binary you asked for if it was found, or undef if it was not.

If called in a list context and the global variable $INSTANCES is a true value, it will return a list of the full paths to instances of the binary where found in PATH, or an empty list if it was not found.

AUTHOR

Michael G Schwern <schwern@pobox.com>