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Fix memory leaks in ValidateSchema #3005

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Merged
merged 1 commit into from
Oct 27, 2023
Merged

Fix memory leaks in ValidateSchema #3005

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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 leaks in ValidateSchema
[Issue #3005 - @martinhsv, @zimmerle]
- Add support for expirevar action
[Issue #1803, #3001 - @martinhsv]
- Fix: lmdb regex match on non-null terminated string
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89 changes: 40 additions & 49 deletions src/operators/validate_schema.cc
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
/*
* ModSecurity, http://www.modsecurity.org/
* Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
* Copyright (c) 2015 - 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* You may not use this file except in compliance with
* the License. You may obtain a copy of the License at
Expand Down Expand Up @@ -39,97 +39,88 @@ bool ValidateSchema::init(const std::string &file, std::string *error) {
}


bool ValidateSchema::evaluate(Transaction *t,
bool ValidateSchema::evaluate(Transaction *transaction,
const std::string &str) {
int rc;

m_parserCtx = xmlSchemaNewParserCtxt(m_resource.c_str());
if (m_parserCtx == NULL) {
if (transaction->m_xml->m_data.doc == NULL) {
ms_dbg_a(transaction, 4, "XML document tree could not be found for " \
"schema validation.");
return true;
}

if (transaction->m_xml->m_data.well_formed != 1) {
ms_dbg_a(transaction, 4, "XML: Schema validation failed because " \
"content is not well formed.");
return true;
}

xmlSchemaParserCtxtPtr parserCtx = xmlSchemaNewParserCtxt(m_resource.c_str());
if (parserCtx == NULL) {
std::stringstream err;
err << "XML: Failed to load Schema from file: ";
err << m_resource;
err << ". ";
if (m_err.empty() == false) {
err << m_err;
}
ms_dbg_a(t, 4, err.str());
ms_dbg_a(transaction, 4, err.str());
return true;
}

xmlSchemaSetParserErrors(m_parserCtx,
xmlSchemaSetParserErrors(parserCtx,
(xmlSchemaValidityErrorFunc)error_load,
(xmlSchemaValidityWarningFunc)warn_load, &m_err);

xmlThrDefSetGenericErrorFunc(m_parserCtx,
xmlThrDefSetGenericErrorFunc(parserCtx,
null_error);

xmlSetGenericErrorFunc(m_parserCtx,
xmlSetGenericErrorFunc(parserCtx,
null_error);

m_schema = xmlSchemaParse(m_parserCtx);
if (m_schema == NULL) {
xmlSchemaPtr schema = xmlSchemaParse(parserCtx);
if (schema == NULL) {
std::stringstream err;
err << "XML: Failed to load Schema: ";
err << m_resource;
err << ".";
if (m_err.empty() == false) {
err << " " << m_err;
}
ms_dbg_a(t, 4, err.str());
xmlSchemaFreeParserCtxt(m_parserCtx);
ms_dbg_a(transaction, 4, err.str());
xmlSchemaFreeParserCtxt(parserCtx);
return true;
}

m_validCtx = xmlSchemaNewValidCtxt(m_schema);
if (m_validCtx == NULL) {
xmlSchemaValidCtxtPtr validCtx = xmlSchemaNewValidCtxt(schema);
if (validCtx == NULL) {
std::stringstream err("XML: Failed to create validation context.");
if (m_err.empty() == false) {
err << " " << m_err;
}
ms_dbg_a(t, 4, err.str());
ms_dbg_a(transaction, 4, err.str());
xmlSchemaFree(schema);
xmlSchemaFreeParserCtxt(parserCtx);
return true;
}

/* Send validator errors/warnings to msr_log */
xmlSchemaSetValidErrors(m_validCtx,
xmlSchemaSetValidErrors(validCtx,
(xmlSchemaValidityErrorFunc)error_runtime,
(xmlSchemaValidityWarningFunc)warn_runtime, t);
(xmlSchemaValidityWarningFunc)warn_runtime, transaction);

if (t->m_xml->m_data.doc == NULL) {
ms_dbg_a(t, 4, "XML document tree could not be found for " \
"schema validation.");
return true;
}
int rc = xmlSchemaValidateDoc(validCtx, transaction->m_xml->m_data.doc);

if (t->m_xml->m_data.well_formed != 1) {
ms_dbg_a(t, 4, "XML: Schema validation failed because " \
"content is not well formed.");
return true;
}

/* Make sure there were no other generic processing errors */
/*
if (msr->msc_reqbody_error) {
ms_dbg_a(t, 4, "XML: Schema validation could not proceed due to previous"
" processing errors.");
return true;
}
*/

rc = xmlSchemaValidateDoc(m_validCtx, t->m_xml->m_data.doc);
xmlSchemaFreeValidCtxt(validCtx);
xmlSchemaFree(schema);
xmlSchemaFreeParserCtxt(parserCtx);
if (rc != 0) {
ms_dbg_a(t, 4, "XML: Schema validation failed.");
xmlSchemaFree(m_schema);
xmlSchemaFreeParserCtxt(m_parserCtx);
ms_dbg_a(transaction, 4, "XML: Schema validation failed.");
return true; /* No match. */
} else {
ms_dbg_a(transaction, 4, "XML: Successfully validated payload against " \
"Schema: " + m_resource);
return false;
}

ms_dbg_a(t, 4, "XML: Successfully validated payload against " \
"Schema: " + m_resource);
xmlSchemaFree(m_schema);
xmlSchemaFreeParserCtxt(m_parserCtx);

return false;
}

#endif
Expand Down
26 changes: 3 additions & 23 deletions src/operators/validate_schema.h
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
/*
* ModSecurity, http://www.modsecurity.org/
* Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
* Copyright (c) 2015 - 2023 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* You may not use this file except in compliance with
* the License. You may obtain a copy of the License at
Expand Down Expand Up @@ -36,27 +36,10 @@ namespace operators {
class ValidateSchema : public Operator {
public:
/** @ingroup ModSecurity_Operator */
#ifndef WITH_LIBXML2
explicit ValidateSchema(std::unique_ptr<RunTimeString> param)
: Operator("ValidateSchema", std::move(param)) { }
#else
explicit ValidateSchema(std::unique_ptr<RunTimeString> param)
: Operator("ValidateSchema", std::move(param)),
m_parserCtx(NULL),
m_validCtx(NULL),
m_schema(NULL) { }
~ValidateSchema() {
/*
if (m_schema != NULL) {
xmlSchemaFree(m_schema);
m_schema = NULL;
}
*/
if (m_validCtx != NULL) {
xmlSchemaFreeValidCtxt(m_validCtx);
m_validCtx = NULL;
}
}
~ValidateSchema() { }
#ifdef WITH_LIBXML2

bool evaluate(Transaction *transaction, const std::string &str) override;
bool init(const std::string &file, std::string *error) override;
Expand Down Expand Up @@ -129,9 +112,6 @@ class ValidateSchema : public Operator {
}

private:
xmlSchemaParserCtxtPtr m_parserCtx;
xmlSchemaValidCtxtPtr m_validCtx;
xmlSchemaPtr m_schema;
std::string m_resource;
std::string m_err;
#endif
Expand Down