We have a problem with an internal mod_perl2 webapp that uses XML::LibXML.

For some reason it segfaults when we try to save a form with this XML:

<?xml version="1.0" encoding="UTF-8"?> 
 <lom xmlns="http://www.imsglobal.org/xsd/imsmd_v1p2" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xsi:schemaLocation="http://www.imsglobal.org/xsd/imsmd_v1p2p2.xsd"> 
 <general> 
 <title> 
 <langstring lang="nb">Poteten - skadelig eller bra for oss?</langstri
+ng> 
 <langstring lang="nn">Er poteten skadeleg eller bra for oss?</langstr
+ing> 
 </title> 
 </general> 
 </lom>

[download]

Segfault:

#0  0xb7699e5e in xmlDictOwns () from /usr/lib/libxml2.so.2
#1  0xb75fe790 in xmlFreeNodeList () from /usr/lib/libxml2.so.2
#2  0xb75fe734 in xmlFreeNodeList () from /usr/lib/libxml2.so.2
#3  0xb75fe734 in xmlFreeNodeList () from /usr/lib/libxml2.so.2
#4  0xb75fe8fa in xmlFreeNode () from /usr/lib/libxml2.so.2
#5  0xb75b3305 in PmmFreeNode () from /usr/lib/perl5/auto/XML/LibXML/L
+ibXML.so
#6  0xb75b33fd in PmmREFCNT_dec () from /usr/lib/perl5/auto/XML/LibXML
+/LibXML.so
#7  0xb75b33df in PmmREFCNT_dec () from /usr/lib/perl5/auto/XML/LibXML
+/LibXML.so
#8  0xb75981aa in XS_XML__LibXML__Node_DESTROY () from /usr/lib/perl5/
+auto/XML/LibXML/LibXML.so
#9  0xb786d3b9 in Perl_pp_entersub () from /usr/lib/libperl.so.5.8
#10 0xb7804f10 in Perl_get_cv () from /usr/lib/libperl.so.5.8
#11 0xb7808cf1 in Perl_call_sv () from /usr/lib/libperl.so.5.8
#12 0xb7870079 in Perl_sv_clear () from /usr/lib/libperl.so.5.8
#13 0xb7870922 in Perl_sv_free () from /usr/lib/libperl.so.5.8
#14 0xb787039a in Perl_sv_clear () from /usr/lib/libperl.so.5.8
#15 0xb7870922 in Perl_sv_free () from /usr/lib/libperl.so.5.8
#16 0xb7895052 in Perl_free_tmps () from /usr/lib/libperl.so.5.8
#17 0xb7865a1e in Perl_pp_nextstate () from /usr/lib/libperl.so.5.8
#18 0xb7865917 in Perl_runops_standard () from /usr/lib/libperl.so.5.8
#19 0xb7804ef0 in Perl_get_cv () from /usr/lib/libperl.so.5.8
#20 0xb7808cf1 in Perl_call_sv () from /usr/lib/libperl.so.5.8
#21 0xb7918b7f in modperl_callback () from /usr/lib/apache2/modules/mo
+d_perl.so
#22 0xb7919451 in modperl_callback_run_handlers () from /usr/lib/apach
+e2/modules/mod_perl.so
#23 0xb79196ff in modperl_callback_per_dir () from /usr/lib/apache2/mo
+dules/mod_perl.so
#24 0xb7913f61 in modperl_response_finish () from /usr/lib/apache2/mod
+ules/mod_perl.so
#25 0xb79141e2 in modperl_response_handler_cgi () from /usr/lib/apache
+2/modules/mod_perl.so
#26 0x08077e48 in ap_run_handler ()
#27 0x080781cc in ap_invoke_handler ()
#28 0x08069c7f in ap_process_request ()
#29 0x08064c52 in _start ()

[download]

I have some problems understanding exactly what to look for from this dump.

Can anyone give me some pointers as to how to understand this one?

I'm not 100% sure it's XML::LibXML that is the culprit, but from the coredump I assume it is.

Filed a bug here: http://rt.cpan.org/Public/Bug/Display.html?id=30610

In reply to XML::LibXML::Node::DESTROY causes segfault in mod_perl2 by robins

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