From 3d7b555aa843b026c9dcb6b0f855af1d358ef2ba Mon Sep 17 00:00:00 2001
From: Henrique Nakashima <hnakashima@chromium.org>
Date: Tue, 17 Jul 2018 20:47:27 +0000
Subject: Limit recursion depth for CXFA_DocumentParser::NormalLoader().

Bug: chromium:849143
Change-Id: I973bb3be6151ac3afad850533cb735c03e9f3d2c
Reviewed-on: https://pdfium-review.googlesource.com/38210
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
---
 xfa/fxfa/parser/cxfa_document_parser.cpp | 7 +++++++
 xfa/fxfa/parser/cxfa_document_parser.h   | 1 +
 2 files changed, 8 insertions(+)

diff --git a/xfa/fxfa/parser/cxfa_document_parser.cpp b/xfa/fxfa/parser/cxfa_document_parser.cpp
index 599662a160..8e5ff9fbde 100644
--- a/xfa/fxfa/parser/cxfa_document_parser.cpp
+++ b/xfa/fxfa/parser/cxfa_document_parser.cpp
@@ -9,6 +9,7 @@
 #include <utility>
 #include <vector>
 
+#include "core/fxcrt/autorestorer.h"
 #include "core/fxcrt/cfx_memorystream.h"
 #include "core/fxcrt/cfx_widetextbuf.h"
 #include "core/fxcrt/fx_codepage.h"
@@ -768,6 +769,12 @@ CXFA_Node* CXFA_DocumentParser::NormalLoader(CXFA_Node* pXFANode,
                                              CFX_XMLNode* pXMLDoc,
                                              XFA_PacketType ePacketID,
                                              bool bUseAttribute) {
+  constexpr const unsigned long kMaxExecuteRecursion = 1000;
+  if (m_ExecuteRecursionDepth > kMaxExecuteRecursion)
+    return nullptr;
+  AutoRestorer<unsigned long> restorer(&m_ExecuteRecursionDepth);
+  ++m_ExecuteRecursionDepth;
+
   bool bOneOfPropertyFound = false;
   for (CFX_XMLNode* pXMLChild = pXMLDoc->GetFirstChild(); pXMLChild;
        pXMLChild = pXMLChild->GetNextSibling()) {
diff --git a/xfa/fxfa/parser/cxfa_document_parser.h b/xfa/fxfa/parser/cxfa_document_parser.h
index 04ed5abb15..4e75db935a 100644
--- a/xfa/fxfa/parser/cxfa_document_parser.h
+++ b/xfa/fxfa/parser/cxfa_document_parser.h
@@ -75,6 +75,7 @@ class CXFA_DocumentParser {
   std::unique_ptr<CFX_XMLDocument> xml_doc_;
   // TODO(dsinclair): Figure out who owns this.
   CXFA_Node* m_pRootNode = nullptr;
+  unsigned long m_ExecuteRecursionDepth = 0;
 };
 
 #endif  // XFA_FXFA_PARSER_CXFA_DOCUMENT_PARSER_H_
-- 
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