Ubuntu Manpage: perl5243delta - what is new for perl v5.24.3

Provided by: perl-doc_5.34.0-3ubuntu1.3_all

NAME

       perl5243delta - what is new for perl v5.24.3

DESCRIPTION

       This document describes differences between the 5.24.2 release and the 5.24.3 release.

       If you are upgrading from an earlier release such as 5.24.1, first read perl5242delta,
       which describes differences between 5.24.1 and 5.24.2.

Security

   [CVE-2017-12837] Heap buffer overflow in regular expression compiler
       Compiling certain regular expression patterns with the case-insensitive modifier could
       cause a heap buffer overflow and crash perl.  This has now been fixed.  [GH #16021]
       <https://github.com/Perl/perl5/issues/16021>

   [CVE-2017-12883] Buffer over-read in regular expression parser
       For certain types of syntax error in a regular expression pattern, the error message could
       either contain the contents of a random, possibly large, chunk of memory, or could crash
       perl.  This has now been fixed.  [GH #16025] <https://github.com/Perl/perl5/issues/16025>

   [CVE-2017-12814] $ENV{$key} stack buffer overflow on Windows
       A possible stack buffer overflow in the %ENV code on Windows has been fixed by removing
       the buffer completely since it was superfluous anyway.  [GH #16051]
       <https://github.com/Perl/perl5/issues/16051>

Incompatible Changes

       There are no changes intentionally incompatible with 5.24.2.  If any exist, they are bugs,
       and we request that you submit a report.  See "Reporting Bugs" below.

Modules and Pragmata

   Updated Modules and Pragmata
       •   Module::CoreList has been upgraded from version 5.20170715_24 to 5.20170922_24.

       •   POSIX has been upgraded from version 1.65 to 1.65_01.

       •   Time::HiRes has been upgraded from version 1.9733 to 1.9741.

           [GH #15396] <https://github.com/Perl/perl5/issues/15396> [GH #15401]
           <https://github.com/Perl/perl5/issues/15401> [GH #15524]
           <https://github.com/Perl/perl5/issues/15524> [cpan #120032]
           <https://rt.cpan.org/Public/Bug/Display.html?id=120032>

Configuration and Compilation

       •   When building with GCC 6 and link-time optimization (the -flto option to gcc),
           Configure was treating all probed symbols as present on the system, regardless of
           whether they actually exist.  This has been fixed.  [GH #15322]
           <https://github.com/Perl/perl5/issues/15322>

       •   Configure now aborts if both "-Duselongdouble" and "-Dusequadmath" are requested.  [GH
           #14944] <https://github.com/Perl/perl5/issues/14944>

       •   Fixed a bug in which Configure could append "-quadmath" to the archname even if it was
           already present.  [GH #15423] <https://github.com/Perl/perl5/issues/15423>

       •   Clang builds with "-DPERL_GLOBAL_STRUCT" or "-DPERL_GLOBAL_STRUCT_PRIVATE" have been
           fixed (by disabling Thread Safety Analysis for these configurations).

Platform Support

   Platform-Specific Notes
       VMS
           •   "configure.com" now recognizes the VSI-branded C compiler.

       Windows
           •   Building XS modules with GCC 6 in a 64-bit build of Perl failed due to incorrect
               mapping of "strtoll" and "strtoull".  This has now been fixed.  [GH #16074]
               <https://github.com/Perl/perl5/issues/16074> [cpan #121683]
               <https://rt.cpan.org/Public/Bug/Display.html?id=121683> [cpan #122353]
               <https://rt.cpan.org/Public/Bug/Display.html?id=122353>

Selected Bug Fixes

       •   "/@0{0*->@*/*0" and similar contortions used to crash, but no longer do, but merely
           produce a syntax error.  [GH #15333] <https://github.com/Perl/perl5/issues/15333>

       •   "do" or "require" with an argument which is a reference or typeglob which, when
           stringified, contains a null character, started crashing in Perl 5.20, but has now
           been fixed.  [GH #15337] <https://github.com/Perl/perl5/issues/15337>

       •   Expressions containing an "&&" or "||" operator (or their synonyms "and" and "or")
           were being compiled incorrectly in some cases.  If the left-hand side consisted of
           either a negated bareword constant or a negated "do {}" block containing a constant
           expression, and the right-hand side consisted of a negated non-foldable expression,
           one of the negations was effectively ignored.  The same was true of "if" and "unless"
           statement modifiers, though with the left-hand and right-hand sides swapped.  This
           long-standing bug has now been fixed.  [GH #15285]
           <https://github.com/Perl/perl5/issues/15285>

       •   "reset" with an argument no longer crashes when encountering stash entries other than
           globs.  [GH #15314] <https://github.com/Perl/perl5/issues/15314>

       •   Assignment of hashes to, and deletion of, typeglobs named *:::::: no longer causes
           crashes.  [GH #15307] <https://github.com/Perl/perl5/issues/15307>

       •   Assignment variants of any bitwise ops under the "bitwise" feature would crash if the
           left-hand side was an array or hash.  [GH #15346]
           <https://github.com/Perl/perl5/issues/15346>

       •   "socket" now leaves the error code returned by the system in $! on failure.  [GH
           #15383] <https://github.com/Perl/perl5/issues/15383>

       •   Parsing bad POSIX charclasses no longer leaks memory.  [GH #15382]
           <https://github.com/Perl/perl5/issues/15382>

       •   Since Perl 5.20, line numbers have been off by one when perl is invoked with the -x
           switch.  This has been fixed.  [GH #15413]
           <https://github.com/Perl/perl5/issues/15413>

       •   Some obscure cases of subroutines and file handles being freed at the same time could
           result in crashes, but have been fixed.  The crash was introduced in Perl 5.22.  [GH
           #15435] <https://github.com/Perl/perl5/issues/15435>

       •   Some regular expression parsing glitches could lead to assertion failures with regular
           expressions such as "/(?<=/" and "/(?<!/".  This has now been fixed.  [GH #15332]
           <https://github.com/Perl/perl5/issues/15332>

       •   "gethostent" and similar functions now perform a null check internally, to avoid
           crashing with the torsocks library.  This was a regression from Perl 5.22.  [GH
           #15478] <https://github.com/Perl/perl5/issues/15478>

       •   Mentioning the same constant twice in a row (which is a syntax error) no longer fails
           an assertion under debugging builds.  This was a regression from Perl 5.20.  [GH
           #15017] <https://github.com/Perl/perl5/issues/15017>

       •   In Perl 5.24 "fchown" was changed not to accept negative one as an argument because in
           some platforms that is an error.  However, in some other platforms that is an
           acceptable argument.  This change has been reverted.  [GH #15523]
           <https://github.com/Perl/perl5/issues/15523>.

       •   "@{x" followed by a newline where "x" represents a control or non-ASCII character no
           longer produces a garbled syntax error message or a crash.  [GH #15518]
           <https://github.com/Perl/perl5/issues/15518>

       •   A regression in Perl 5.24 with "tr/\N{U+...}/foo/" when the code point was between 128
           and 255 has been fixed.  [GH #15475] <https://github.com/Perl/perl5/issues/15475>.

       •   Many issues relating to "printf "%a"" of hexadecimal floating point were fixed.  In
           addition, the "subnormals" (formerly known as "denormals") floating point numbers are
           now supported both with the plain IEEE 754 floating point numbers (64-bit or 128-bit)
           and the x86 80-bit "extended precision".  Note that subnormal hexadecimal floating
           point literals will give a warning about "exponent underflow".  [GH #15495]
           <https://github.com/Perl/perl5/issues/15495> [GH #15502]
           <https://github.com/Perl/perl5/issues/15502> [GH #15503]
           <https://github.com/Perl/perl5/issues/15503> [GH #15504]
           <https://github.com/Perl/perl5/issues/15504> [GH #15505]
           <https://github.com/Perl/perl5/issues/15505> [GH #15510]
           <https://github.com/Perl/perl5/issues/15510> [GH #15512]
           <https://github.com/Perl/perl5/issues/15512>

       •   The parser could sometimes crash if a bareword came after "evalbytes".  [GH #15586]
           <https://github.com/Perl/perl5/issues/15586>

       •   Fixed a place where the regex parser was not setting the syntax error correctly on a
           syntactically incorrect pattern.  [GH #15565]
           <https://github.com/Perl/perl5/issues/15565>

       •   A vulnerability in Perl's "sprintf" implementation has been fixed by avoiding a
           possible memory wrap.  [GH #15970] <https://github.com/Perl/perl5/issues/15970>

Acknowledgements

Perl 5.24.3 represents approximately 2 months of development since Perl 5.24.2 and
contains approximately 3,200 lines of changes across 120 files from 23 authors.

Excluding auto-generated files, documentation and release tools, there were approximately
1,600 lines of changes to 56 .pm, .t, .c and .h files.

Perl continues to flourish into its third decade thanks to a vibrant community of users
and developers. The following people are known to have contributed the improvements that
became Perl 5.24.3:

Aaron Crane, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan Collins, Daniel Dragan, Dave
Cross, David Mitchell, Eric Herman, Father Chrysostomos, H.Merijn Brand, Hugo van der
Sanden, James E Keenan, Jarkko Hietaniemi, John SJ Anderson, Karl Williamson, Ken Brown,
Lukas Mai, Matthew Horsfall, Stevan Little, Steve Hay, Steven Humphrey, Tony Cook, Yves
Orton.

The list above is almost certainly incomplete as it is automatically generated from
version control history. In particular, it does not include the names of the (very much
appreciated) contributors who reported issues to the Perl bug tracker.

Many of the changes included in this version originated in the CPAN modules included in
Perl's core. We're grateful to the entire CPAN community for helping Perl to flourish.

For a more complete list of all of Perl's historical contributors, please see the AUTHORS
file in the Perl source distribution.

Reporting Bugs

       If you find what you think is a bug, you might check the articles recently posted to the
       comp.lang.perl.misc newsgroup and the perl bug database at <https://rt.perl.org/> .  There
       may also be information at <http://www.perl.org/> , the Perl Home Page.

       If you believe you have an unreported bug, please run the perlbug program included with
       your release.  Be sure to trim your bug down to a tiny but sufficient test case.  Your bug
       report, along with the output of "perl -V", will be sent off to perlbug@perl.org to be
       analysed by the Perl porting team.

       If the bug you are reporting has security implications which make it inappropriate to send
       to a publicly archived mailing list, then see "SECURITY VULNERABILITY CONTACT INFORMATION"
       in perlsec for details of how to report the issue.