1=encoding utf8 2 3=head1 NAME 4 5perl5241delta - what is new for perl v5.24.1 6 7=head1 DESCRIPTION 8 9This document describes differences between the 5.24.0 release and the 5.24.1 10release. 11 12If you are upgrading from an earlier release such as 5.22.0, first read 13L<perl5240delta>, which describes differences between 5.22.0 and 5.24.0. 14 15=head1 Security 16 17=head2 B<-Di> switch is now required for PerlIO debugging output 18 19Previously PerlIO debugging output would be sent to the file specified by the 20C<PERLIO_DEBUG> environment variable if perl wasn't running setuid and the 21B<-T> or B<-t> switches hadn't been parsed yet. 22 23If perl performed output at a point where it hadn't yet parsed its switches 24this could result in perl creating or overwriting the file named by 25C<PERLIO_DEBUG> even when the B<-T> switch had been supplied. 26 27Perl now requires the B<-Di> switch to produce PerlIO debugging output. By 28default this is written to C<stderr>, but can optionally be redirected to a 29file by setting the C<PERLIO_DEBUG> environment variable. 30 31If perl is running setuid or the B<-T> switch was supplied C<PERLIO_DEBUG> is 32ignored and the debugging output is sent to C<stderr> as for any other B<-D> 33switch. 34 35=head2 Core modules and tools no longer search F<"."> for optional modules 36 37The tools and many modules supplied in core no longer search the default 38current directory entry in L<C<@INC>|perlvar/@INC> for optional modules. For 39example, L<Storable> will remove the final F<"."> from C<@INC> before trying to 40load L<Log::Agent>. 41 42This prevents an attacker injecting an optional module into a process run by 43another user where the current directory is writable by the attacker, e.g. the 44F</tmp> directory. 45 46In most cases this removal should not cause problems, but difficulties were 47encountered with L<base>, which treats every module name supplied as optional. 48These difficulties have not yet been resolved, so for this release there are no 49changes to L<base>. We hope to have a fix for L<base> in Perl 5.24.2. 50 51To protect your own code from this attack, either remove the default F<"."> 52entry from C<@INC> at the start of your script, so: 53 54 #!/usr/bin/perl 55 use strict; 56 ... 57 58becomes: 59 60 #!/usr/bin/perl 61 BEGIN { pop @INC if $INC[-1] eq '.' } 62 use strict; 63 ... 64 65or for modules, remove F<"."> from a localized C<@INC>, so: 66 67 my $can_foo = eval { require Foo; } 68 69becomes: 70 71 my $can_foo = eval { 72 local @INC = @INC; 73 pop @INC if $INC[-1] eq '.'; 74 require Foo; 75 }; 76 77=head1 Incompatible Changes 78 79Other than the security changes above there are no changes intentionally 80incompatible with Perl 5.24.0. If any exist, they are bugs, and we request 81that you submit a report. See L</Reporting Bugs> below. 82 83=head1 Modules and Pragmata 84 85=head2 Updated Modules and Pragmata 86 87=over 4 88 89=item * 90 91L<Archive::Tar> has been upgraded from version 2.04 to 2.04_01. 92 93=item * 94 95L<bignum> has been upgraded from version 0.42 to 0.42_01. 96 97=item * 98 99L<CPAN> has been upgraded from version 2.11 to 2.11_01. 100 101=item * 102 103L<Digest> has been upgraded from version 1.17 to 1.17_01. 104 105=item * 106 107L<Digest::SHA> has been upgraded from version 5.95 to 5.95_01. 108 109=item * 110 111L<Encode> has been upgraded from version 2.80 to 2.80_01. 112 113=item * 114 115L<ExtUtils::MakeMaker> has been upgraded from version 7.10_01 to 7.10_02. 116 117=item * 118 119L<File::Fetch> has been upgraded from version 0.48 to 0.48_01. 120 121=item * 122 123L<File::Spec> has been upgraded from version 3.63 to 3.63_01. 124 125=item * 126 127L<HTTP::Tiny> has been upgraded from version 0.056 to 0.056_001. 128 129=item * 130 131L<IO> has been upgraded from version 1.36 to 1.36_01. 132 133=item * 134 135The IO-Compress modules have been upgraded from version 2.069 to 2.069_001. 136 137=item * 138 139L<IPC::Cmd> has been upgraded from version 0.92 to 0.92_01. 140 141=item * 142 143L<JSON::PP> has been upgraded from version 2.27300 to 2.27300_01. 144 145=item * 146 147L<Locale::Maketext> has been upgraded from version 1.26 to 1.26_01. 148 149=item * 150 151L<Locale::Maketext::Simple> has been upgraded from version 0.21 to 0.21_01. 152 153=item * 154 155L<Memoize> has been upgraded from version 1.03 to 1.03_01. 156 157=item * 158 159L<Module::CoreList> has been upgraded from version 5.20160506 to 5.20170114_24. 160 161=item * 162 163L<Net::Ping> has been upgraded from version 2.43 to 2.43_01. 164 165=item * 166 167L<Parse::CPAN::Meta> has been upgraded from version 1.4417 to 1.4417_001. 168 169=item * 170 171L<Pod::Html> has been upgraded from version 1.22 to 1.2201. 172 173=item * 174 175L<Pod::Perldoc> has been upgraded from version 3.25_02 to 3.25_03. 176 177=item * 178 179L<Storable> has been upgraded from version 2.56 to 2.56_01. 180 181=item * 182 183L<Sys::Syslog> has been upgraded from version 0.33 to 0.33_01. 184 185=item * 186 187L<Test> has been upgraded from version 1.28 to 1.28_01. 188 189=item * 190 191L<Test::Harness> has been upgraded from version 3.36 to 3.36_01. 192 193=item * 194 195L<XSLoader> has been upgraded from version 0.21 to 0.22, fixing a security hole 196in which binary files could be loaded from a path outside of C<@INC>. 197L<[perl #128528]|https://rt.perl.org/Public/Bug/Display.html?id=128528> 198 199=back 200 201=head1 Documentation 202 203=head2 Changes to Existing Documentation 204 205=head3 L<perlapio> 206 207=over 4 208 209=item * 210 211The documentation of C<PERLIO_DEBUG> has been updated. 212 213=back 214 215=head3 L<perlrun> 216 217=over 4 218 219=item * 220 221The new B<-Di> switch has been documented, and the documentation of 222C<PERLIO_DEBUG> has been updated. 223 224=back 225 226=head1 Testing 227 228=over 4 229 230=item * 231 232A new test script, F<t/run/switchDx.t>, has been added to test that the new 233B<-Di> switch is working correctly. 234 235=back 236 237=head1 Selected Bug Fixes 238 239=over 4 240 241=item * 242 243The change to hashbang redirection introduced in Perl 5.24.0, whereby perl 244would redirect to another interpreter (Perl 6) if it found a hashbang path 245which contains "perl" followed by "6", has been reverted because it broke in 246cases such as C<#!/opt/perl64/bin/perl>. 247 248=back 249 250=head1 Acknowledgements 251 252Perl 5.24.1 represents approximately 8 months of development since Perl 5.24.0 253and contains approximately 8,100 lines of changes across 240 files from 18 254authors. 255 256Excluding auto-generated files, documentation and release tools, there were 257approximately 2,200 lines of changes to 170 .pm, .t, .c and .h files. 258 259Perl continues to flourish into its third decade thanks to a vibrant community 260of users and developers. The following people are known to have contributed 261the improvements that became Perl 5.24.1: 262 263Aaron Crane, Alex Vandiver, Aristotle Pagaltzis, Chad Granum, Chris 'BinGOs' 264Williams, Craig A. Berry, Father Chrysostomos, James E Keenan, Jarkko 265Hietaniemi, Karen Etheridge, Leon Timmermans, Matthew Horsfall, Ricardo Signes, 266Sawyer X, Sébastien Aperghis-Tramoni, Stevan Little, Steve Hay, Tony Cook. 267 268The list above is almost certainly incomplete as it is automatically generated 269from version control history. In particular, it does not include the names of 270the (very much appreciated) contributors who reported issues to the Perl bug 271tracker. 272 273Many of the changes included in this version originated in the CPAN modules 274included in Perl's core. We're grateful to the entire CPAN community for 275helping Perl to flourish. 276 277For a more complete list of all of Perl's historical contributors, please see 278the F<AUTHORS> file in the Perl source distribution. 279 280=head1 Reporting Bugs 281 282If you find what you think is a bug, you might check the articles recently 283posted to the comp.lang.perl.misc newsgroup and the Perl bug database at 284L<https://rt.perl.org/> . There may also be information at 285L<http://www.perl.org/> , the Perl Home Page. 286 287If you believe you have an unreported bug, please run the L<perlbug> program 288included with your release. Be sure to trim your bug down to a tiny but 289sufficient test case. Your bug report, along with the output of C<perl -V>, 290will be sent off to perlbug@perl.org to be analysed by the Perl porting team. 291 292If the bug you are reporting has security implications which make it 293inappropriate to send to a publicly archived mailing list, then see 294L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION> for details of how to 295report the issue. 296 297=head1 SEE ALSO 298 299The F<Changes> file for an explanation of how to view exhaustive details on 300what changed. 301 302The F<INSTALL> file for how to build Perl. 303 304The F<README> file for general stuff. 305 306The F<Artistic> and F<Copying> files for copyright information. 307 308=cut 309