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Fix memory leak of ValidateDTD's dtd object #2478

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Fix memory leak of ValidateDTD's dtd object #2478

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2 changes: 2 additions & 0 deletions CHANGES
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Original file line number Diff line number Diff line change
@@ -1,6 +1,8 @@
v3.x.y - YYYY-MMM-DD (to be released)
-------------------------------------

- Fix memory leak of ValidateDTD's m_dtd
[#2469 - @martinhsv, @zimmerle]
- Replaces put with setenv in SetEnv action
[#2469 - @martinhsv, @WGH-, @zimmerle]
- Using a custom VariableMatch* implementation
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10 changes: 4 additions & 6 deletions src/operators/validate_dtd.cc
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Expand Up @@ -47,10 +47,8 @@ bool ValidateDTD::evaluate(Transaction *transaction,
const RuleWithActions *rule,
const bpstd::string_view &input,
RuleMessage *ruleMessage) {
xmlValidCtxtPtr cvp;

m_dtd = xmlParseDTD(NULL, (const xmlChar *)m_resource.c_str());
if (m_dtd == NULL) {
XmlDtdPtrManager m_dtd(xmlParseDTD(NULL, (const xmlChar *)m_resource.c_str()));
if (m_dtd.get() == NULL) {
std::string err = std::string("XML: Failed to load DTD: ") \
+ m_resource;
ms_dbg_a(transaction, 4, err);
Expand Down Expand Up @@ -79,7 +77,7 @@ bool ValidateDTD::evaluate(Transaction *transaction,
}
#endif

cvp = xmlNewValidCtxt();
xmlValidCtxtPtr cvp = xmlNewValidCtxt();
if (cvp == NULL) {
ms_dbg_a(transaction, 4,
"XML: Failed to create a validation context.");
Expand All @@ -91,7 +89,7 @@ bool ValidateDTD::evaluate(Transaction *transaction,
cvp->warning = (xmlSchemaValidityErrorFunc)warn_runtime;
cvp->userData = transaction;

if (!xmlValidateDtd(cvp, transaction->m_xml->m_data.doc, m_dtd)) {
if (!xmlValidateDtd(cvp, transaction->m_xml->m_data.doc, m_dtd.get())) {
ms_dbg_a(transaction, 4, "XML: DTD validation failed.");
xmlFreeValidCtxt(cvp);
return true;
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23 changes: 17 additions & 6 deletions src/operators/validate_dtd.h
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Expand Up @@ -33,18 +33,30 @@
namespace modsecurity {
namespace operators {

class ValidateDTD : public Operator {
class XmlDtdPtrManager {
public:
/** @ingroup ModSecurity_Operator */
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This marking is further used by doxygen, in order to place this class under the operators sub class.

explicit ValidateDTD(std::unique_ptr<RunTimeString> param)
: Operator("ValidateDTD", std::move(param)) { }
explicit XmlDtdPtrManager(xmlDtdPtr dtd)
: m_dtd(dtd) { }
~XmlDtdPtrManager() {
#ifdef WITH_LIBXML2
~ValidateDTD() {
if (m_dtd != NULL) {
xmlFreeDtd(m_dtd);
m_dtd = NULL;
}
#endif
}
xmlDtdPtr get() const {return m_dtd;}
private:
xmlDtdPtr m_dtd; // The resource being managed
};

class ValidateDTD : public Operator {
public:
/** @ingroup ModSecurity_Operator */
explicit ValidateDTD(std::unique_ptr<RunTimeString> param)
: Operator("ValidateDTD", std::move(param)) { }
#ifdef WITH_LIBXML2
~ValidateDTD() { }

bool evaluate(Transaction *transaction,
const RuleWithActions *rule,
Expand Down Expand Up @@ -93,7 +105,6 @@ class ValidateDTD : public Operator {

private:
std::string m_resource;
xmlDtdPtr m_dtd = NULL;
#endif
};

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