Bug #17669 for Archive-Tar: Corrupt tar file leads to a call to an undefined value

Wed Feb 15 23:24:16 2006 Guest - Ticket created

Subject:

Corrupt tar file leads to a call to an undefined value

If a corrupt tar file is fed into Archive::Tar, it is possible for the unless loop starting at line 278 to exit without defining a valid $entry value. This leads to the module aborting prematurely at line 288 with: Can't call method "is_label" on an undefined value at .../Archive/Tar.pm line 288. As a hack/work around I've put the following on the line before: next if (!defined($entry)); However, there should be a cleaner solution. I don't fully understand whats going on in that bit of code, so my hack is probably ill-advised

Thu Mar 02 10:09:12 2006 kane [...] cpan.org - Correspondence added

On Wed Feb 15 23:24:16 2006, guest wrote: Show quoted text

> If a corrupt tar file is fed into Archive::Tar, it is possible for the > unless loop starting at line 278 to exit without defining a valid $entry > value. This leads to the module aborting prematurely at line 288 with: > > Can't call method "is_label" on an undefined value at .../Archive/Tar.pm > line 288.

Hmm, it actually shouldn't be able to..... the check is done in the code, in an unless statement... ### pass the realname, so we can set it 'proper' right away ### some of the heuristics are done on the name, so important ### to set it ASAP my $entry; { my %extra_args = (); $extra_args{'name'} = $$real_name if defined $real_name; unless( $entry = Archive::Tar::File->new( chunk => $chunk, %extra_args ) ) { $self->_error( qq[Couldn't read chunk at offset $offset] ); next; } } ### ignore labels: ### http://www.gnu.org/manual/tar/html_node/tar_139.html next if $entry->is_label; Do you have a bit of example code that somehow manages to get through this check anyway?

Thu Mar 02 10:09:15 2006 The RT System itself - Status changed from 'new' to 'open'

Fri Mar 03 08:49:17 2006 kane [...] cpan.org - Correspondence added

On Thu Mar 02 10:09:12 2006, KANE wrote: Show quoted text

> unless( $entry = Archive::Tar::File->new( chunk => $chunk, > %extra_args ) > ) { > $self->_error( qq[Couldn't read chunk at offset $offset] ); > next; > }

This actually required a 'next LOOP;' statement rather than just next; This has been fixed in 1.29 -- thank you for reporting

Fri Mar 03 08:49:19 2006 kane [...] cpan.org - Status changed from 'open' to 'resolved'