odd crash in file upload via CGI

[msoulier]

Hey people,

This one is baffling me. I'm moving from a RedHat 7.3 platform to
CentOS 4.3, which includes a move from Perl 5.6.1 to 5.8.5.

I have an upload dialog making use of a CGI with the CGI module that
works fine on the old platform, but all I get on the new platform is an
internal server error, due to no content being sent back to apache.

It would seem that the interpreter is sending nothing, and I'm having a
hell of a time finding out why. Running it on the command line with the
same environment does not produce similar results (thus, the
environment is obviously not similar enough). And yet, it seems like
the interpreter might just be crashing out for some reason.

Suggestions appreciated as to how to troubleshoot this going forward.

Mike

 

[xhoster]

Hey people,

This one is baffling me. I'm moving from a RedHat 7.3 platform to
CentOS 4.3, which includes a move from Perl 5.6.1 to 5.8.5.

I have an upload dialog making use of a CGI with the CGI module that
works fine on the old platform, but all I get on the new platform is an
internal server error, due to no content being sent back to apache.

Does a simple "hello world" CGI work? Does your log file contain anything
useful?

Xho

 

[Ben Morrow]

Hey people,

This one is baffling me. I'm moving from a RedHat 7.3 platform to
CentOS 4.3, which includes a move from Perl 5.6.1 to 5.8.5.

I have an upload dialog making use of a CGI with the CGI module that
works fine on the old platform, but all I get on the new platform is an
internal server error, due to no content being sent back to apache.

It would seem that the interpreter is sending nothing, and I'm having a
hell of a time finding out why. Running it on the command line with the
same environment does not produce similar results (thus, the
environment is obviously not similar enough). And yet, it seems like
the interpreter might just be crashing out for some reason.

Suggestions appreciated as to how to troubleshoot this going forward.

Run it as whatever user it gets run as when it's called as a CGI.
CGI::Carp

Ben

 

[msoulier]

Does a simple "hello world" CGI work? Does your log file contain anything
useful?

CGIs work in general, yes. This CGI works fine in fact, except for this
one feature.

[Mon Jul 31 11:51:46 2006] [error] [client 127.0.0.1] Premature end of
script headers: tug, referer:
https://10.33.15.145/server-manager...nupage=1&.id=85ea497895b72e17ca7a1a8b94edbef3

Basically says that the CGI returned prematurely, as it returning
nothing.

Mike

 

[msoulier]

Run it as whatever user it gets run as when it's called as a CGI.
CGI::Carp

Yeah, tried CGI::Carp already, and ran it as the right user. However, I
just removed and eval call and this error popped up. For some reason
the eval masked the problem. Perhaps it crashed the interpreter, not
sure.

Can't coerce GLOB to string in entersub at
/usr/lib/perl5/site_perl/5.8.0/Persistence/Object/Simple.pm line 125.

So this is apparently my issue. I didn't see it because evaling the
code and checking $@ for some reason did not turn the issue up. Very,
very odd.

Mike

 

[Charles DeRykus]

^^^^^

Yeah, tried CGI::Carp already, and ran it as the right user. However, I
just removed and eval call and this error popped up. For some reason
the eval masked the problem. Perhaps it crashed the interpreter, not
sure.

Can't coerce GLOB to string in entersub at
/usr/lib/perl5/site_perl/5.8.0/Persistence/Object/Simple.pm line 125.

^^^^^

Is the version discrepancy between 5.8.5 and 5.8.0 expected... Could
your environment be picking up older installs...

 

[msoulier]

Is the version discrepancy between 5.8.5 and 5.8.0 expected... Could
your environment be picking up older installs...

I don't believe so, but I suppose I should ask the CentOS people, and
the owner of the Dag repository. I believe that's where the code is
coming from.

Mike

 

[msoulier]

Can't coerce GLOB to string in entersub at
/usr/lib/perl5/site_perl/5.8.0/Persistence/Object/Simple.pm line 125.

And believe it or not, this little bit of code prevents it from
happening.

foreach my $param ($cgi->param)
{
my $val = $cgi->param($param);
my $string = "$val";
}

Seems completely unrelated, but if I don't stringify the incoming
parameters once, then it crashes.

Any perl gurus with black magick to explain this one for me?

Cheers,
Mike

 

[Paul Lalli]

^^^^^
Any perl gurus with black magick to explain this one for me?

5.8.0 is notoriously buggy. You use known-buggy software, you
encounter bugs. Upgrade.

Paul Lalli

 

[msoulier]

5.8.0 is notoriously buggy. You use known-buggy software, you
encounter bugs. Upgrade.

If you'll check the thread, you'll find that I'm running 5.8.5.

Mike

 

[Paul Lalli]

If you'll check the thread, you'll find that I'm running 5.8.5.

If you'll check the paths in the error messages, you'll see you're
using modules from a 5.8.0 installation.

Paul Lalli

 

[msoulier]

If you'll check the paths in the error messages, you'll see you're
using modules from a 5.8.0 installation.

Indeed, as packaged by CentOS. Still, the interpreter is 5.8.5, and I
tried a newer CGI:ersistent and it didn't fix the issue. We seem to
be using the latest Persistence::Object::Simple and the latest
Data:umper, which is where the error appears to be occurring.

Mike