Stack overflow/(very)poor performance if maxOccurs in a schema d efinition is too big e.g. 1000

[Christoffer Dam Bruun <cb...@systematic.dk>]

We run Xerces v1.5.0

We are validating a 1600 bytes xml-msg using StdInParse

sample from our schema file:
<!-- FONKOD -->
<element name="FONKOD">
 <complexType>
  <sequence >
   <element ref="KURSOP" minOccurs="1" maxOccurs="1"/>
   <element ref="LAANOP" minOccurs="1" maxOccurs="10"/>
  </sequence> 
  <attribute name="Fondskode" type="AN12" use="required"/>
  <attribute name="Valutakode" type="AN3"/>
 </complexType>
</element>


If maxOccurs is set to 10 we can validate the msg in 100msec

if maxOccurs is set to 1000 it takes 6sek!

if maxOccurs is set to 10000 we get a stackoverflow:
The entire stack is used for calls to this function: CMNode*
DFAContentModel::buildSyntaxTree(ContentSpecNode* const curNode)
It seems as if Xerces is generating a state in the DFA for each possible
repetition....

/Christoffer





m.v.h.
Christoffer Bruun
email: cb@systematic.dk
tlf: 89432000

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