Limit recursion in CXML_Parser::ParseElement().
BUG=chromium:716526
Change-Id: Idbe4624ab2193cee2931c69ed023dd2c1679d124
Reviewed-on: https://pdfium-review.googlesource.com/4615
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fxcrt/xml/cxml_element.cpp b/core/fxcrt/xml/cxml_element.cpp
index 17caebf..95a6dba 100644
--- a/core/fxcrt/xml/cxml_element.cpp
+++ b/core/fxcrt/xml/cxml_element.cpp
@@ -9,6 +9,15 @@
#include "core/fxcrt/xml/cxml_content.h"
#include "core/fxcrt/xml/cxml_parser.h"
+// static
+std::unique_ptr<CXML_Element> CXML_Element::Parse(const void* pBuffer,
+ size_t size) {
+ CXML_Parser parser;
+ if (!parser.Init(static_cast<const uint8_t*>(pBuffer), size))
+ return nullptr;
+ return parser.ParseElement(nullptr, false);
+}
+
CXML_Element::CXML_Element(const CXML_Element* pParent,
const CFX_ByteStringC& qSpace,
const CFX_ByteStringC& tagname)
diff --git a/core/fxcrt/xml/cxml_parser.cpp b/core/fxcrt/xml/cxml_parser.cpp
index 691a86e..dc3978e 100644
--- a/core/fxcrt/xml/cxml_parser.cpp
+++ b/core/fxcrt/xml/cxml_parser.cpp
@@ -53,6 +53,8 @@
0x1A, 0x1A, 0x01, 0x01,
};
+constexpr int kMaxDepth = 1024;
+
bool g_FXCRT_XML_IsWhiteSpace(uint8_t ch) {
return !!(g_FXCRT_XML_ByteTypes[ch] & FXCRTM_XML_CHARTYPE_SpaceChar);
}
@@ -369,6 +371,16 @@
std::unique_ptr<CXML_Element> CXML_Parser::ParseElement(CXML_Element* pParent,
bool bStartTag) {
+ return ParseElementInternal(pParent, bStartTag, 0);
+}
+
+std::unique_ptr<CXML_Element> CXML_Parser::ParseElementInternal(
+ CXML_Element* pParent,
+ bool bStartTag,
+ int nDepth) {
+ if (nDepth > kMaxDepth)
+ return nullptr;
+
m_nOffset = m_nBufferOffset + static_cast<FX_FILESIZE>(m_dwIndex);
if (IsEOF())
return nullptr;
@@ -476,8 +488,8 @@
bCDATA = false;
iState = 0;
m_dwIndex--;
- std::unique_ptr<CXML_Element> pSubElement(
- ParseElement(pElement.get(), true));
+ std::unique_ptr<CXML_Element> pSubElement =
+ ParseElementInternal(pElement.get(), true, nDepth + 1);
if (!pSubElement)
break;
@@ -529,11 +541,3 @@
pContent->Set(bCDATA, content);
pElement->m_Children.push_back({CXML_Element::Content, pContent});
}
-
-std::unique_ptr<CXML_Element> CXML_Element::Parse(const void* pBuffer,
- size_t size) {
- CXML_Parser parser;
- if (!parser.Init(static_cast<const uint8_t*>(pBuffer), size))
- return nullptr;
- return parser.ParseElement(nullptr, false);
-}
diff --git a/core/fxcrt/xml/cxml_parser.h b/core/fxcrt/xml/cxml_parser.h
index 371edf2..33bd711 100644
--- a/core/fxcrt/xml/cxml_parser.h
+++ b/core/fxcrt/xml/cxml_parser.h
@@ -42,6 +42,10 @@
void InsertCDATASegment(CFX_UTF8Decoder& decoder, CXML_Element* pElement);
private:
+ std::unique_ptr<CXML_Element> ParseElementInternal(CXML_Element* pParent,
+ bool bStartTag,
+ int nDepth);
+
std::unique_ptr<CXML_DataBufAcc> m_pDataAcc;
FX_FILESIZE m_nOffset;
const uint8_t* m_pBuffer;