From qleah@earthlink.net

This is a bug report for perl from qleah@​earthlink.net,
generated with the help of perlbug 1.35 running under perl v5.8.5.

Errno.pm must not trust the user to pass only valid sub references via
EXISTS.

  perl -MErrno -e 'exists $!{[]}'

  Not a subroutine reference at
/usr/lib/perl5/5.8.5/i586-linux-multi-64int-ld/Errno.pm line 216.

Flags​:
  category=core
  severity=medium

From @rgs

Leah (via RT) wrote​:

Errno.pm must not trust the user to pass only valid sub references via
EXISTS.

perl \-MErrno \-e 'exists $\!\{\[\]\}'

Not a subroutine reference at

/usr/lib/perl5/5.8.5/i586-linux-multi-64int-ld/Errno.pm line 216.

Thanks for the report, this has been fixed by change #23423 to the
development version of perl :

Change 23424 by rgs@​valis on 2004/10/25 15​:31​:21

  Fix [perl #32130] Errno.pm must not pass references to "prototype"

Affected files ...

... //depot/perl/ext/Errno/Errno_pm.PL#39 edit
... //depot/perl/ext/Errno/t/Errno.t#3 edit

Differences ...

==== //depot/perl/ext/Errno/Errno_pm.PL#39 (text) ====

@​@​ -377,7 +377,8 @​@​

sub EXISTS {
  my ($self, $errname) = @​_;
- my $proto = prototype($errname);
+ my $r = ref $errname;
+ my $proto = !$r || $r eq 'CODE' ? prototype($errname) : undef;
  defined($proto) && $proto eq "";
}

==== //depot/perl/ext/Errno/t/Errno.t#3 (xtext) ====

@​@​ -13,7 +13,7 @​@​

use Errno;

-print "1..5\n";
+print "1..6\n";

print "not " unless @​Errno​::EXPORT_OK;
print "ok 1\n";
@​@​ -53,3 +53,6 @​@​
}

print "ok 5\n";
+
+eval { exists $!{[]} };
+print $@​ ? "not ok 6\n" : "ok 6\n";

The RT System itself - Status changed from 'new' to 'open'

@rgs - Status changed from 'open' to 'resolved'

From @gbarr

On 25 Oct 2004, at 17​:57, Rafael Garcia-Suarez wrote​:

sub EXISTS {
my ($self, $errname) = @​_;
- my $proto = prototype($errname);
+ my $r = ref $errname;
+ my $proto = !$r || $r eq 'CODE' ? prototype($errname) : undef;

I don't think it should allow passing of code references. It was a
mistake that it ever did. EXISTS should only return true for errno
names that exist on the current system. So

my $proto = ref($errname) || prototype($errname);

should be sufficient because any reference would then cause the
following to fail

 defined\($proto\) && $proto eq "";

}

Graham.