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Merge pull request #669 from leethomason/overflow

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Fix stack overflows
This commit is contained in:
Lee Thomason
2018-04-05 22:56:48 -07:00
committed by GitHub
parent 65b5366a02 e2d02e1623
commit b94eefc7a1
8 changed files with 88 additions and 23 deletions
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1
resources/xmltest-4636783552757760.xml Normal file
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1
resources/xmltest-5330.xml Normal file
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1
resources/xmltest-5720541257269248.xml Normal file
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25
tinyxml2.cpp
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@@ -1004,7 +1004,11 @@ char* XMLNode::ParseDeep( char* p, StrPair* parentEndTag, int* curLineNumPtr )
// 'endTag' is the end tag for this node, it is returned by a call to a child.
// 'parentEnd' is the end tag for the parent, which is filled in and returned.
while( p && *p ) {
XMLDocument::DepthTracker tracker(_document);
if (_document->Error())
return 0;
while( p && *p ) {
XMLNode* node = 0;
p = _document->Identify( p, &node );
@@ -1986,7 +1990,8 @@ const char* XMLDocument::_errorNames[XML_ERROR_COUNT] = {
"XML_ERROR_MISMATCHED_ELEMENT",
"XML_ERROR_PARSING",
"XML_CAN_NOT_CONVERT_TEXT",
"XML_NO_TEXT_NODE"
"XML_NO_TEXT_NODE",
"XML_ELEMENT_DEPTH_EXCEEDED"
};
@@ -2000,6 +2005,7 @@ XMLDocument::XMLDocument( bool processEntities, Whitespace whitespaceMode ) :
_errorLineNum( 0 ),
_charBuffer( 0 ),
_parseCurLineNum( 0 ),
_parsingDepth(0),
_unlinked(),
_elementPool(),
_attributePool(),
@@ -2044,6 +2050,7 @@ void XMLDocument::Clear()
delete [] _charBuffer;
_charBuffer = 0;
_parsingDepth = 0;
#if 0
_textPool.Trace( "text" );
@@ -2377,6 +2384,20 @@ void XMLDocument::Parse()
ParseDeep(p, 0, &_parseCurLineNum );
}
void XMLDocument::PushDepth()
{
_parsingDepth++;
if (_parsingDepth == TINYXML2_MAX_ELEMENT_DEPTH) {
SetError(XML_ELEMENT_DEPTH_EXCEEDED, _parseCurLineNum, "Element nesting is too deep." );
}
}
void XMLDocument::PopDepth()
{
TIXMLASSERT(_parsingDepth > 0);
--_parsingDepth;
}
XMLPrinter::XMLPrinter( FILE* file, bool compact, int depth ) :
_elementJustOpened( false ),
_stack(),

29
tinyxml2.h
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@@ -106,6 +106,13 @@ static const int TIXML2_PATCH_VERSION = 0;
#define TINYXML2_MINOR_VERSION 1
#define TINYXML2_PATCH_VERSION 0
// A fixed element depth limit is problematic. There needs to be a
// limit to avoid a stack overflow. However, that limit varies per
// system, and the capacity of the stack. On the other hand, it's a trivial
// attack that can result from ill, malicious, or even correctly formed XML,
// so there needs to be a limit in place.
static const int TINYXML2_MAX_ELEMENT_DEPTH = 100;
namespace tinyxml2
{
class XMLDocument;
@@ -532,6 +539,7 @@ enum XMLError {
XML_ERROR_PARSING,
XML_CAN_NOT_CONVERT_TEXT,
XML_NO_TEXT_NODE,
XML_ELEMENT_DEPTH_EXCEEDED,
XML_ERROR_COUNT
};
@@ -1650,7 +1658,7 @@ enum Whitespace {
class TINYXML2_LIB XMLDocument : public XMLNode
{
friend class XMLElement;
// Gives access to SetError, but over-access for everything else.
// Gives access to SetError and Push/PopDepth, but over-access for everything else.
// Wishing C++ had "internal" scope.
friend class XMLNode;
friend class XMLText;
@@ -1874,6 +1882,7 @@ private:
int _errorLineNum;
char* _charBuffer;
int _parseCurLineNum;
int _parsingDepth;
// Memory tracking does add some overhead.
// However, the code assumes that you don't
// have a bunch of unlinked nodes around.
@@ -1893,6 +1902,24 @@ private:
void SetError( XMLError error, int lineNum, const char* format, ... );
// Something of an obvious security hole, once it was discovered.
// Either an ill-formed XML or an excessively deep one can overflow
// the stack. Track stack depth, and error out if needed.
class DepthTracker {
public:
DepthTracker(XMLDocument * document) {
this->_document = document;
document->PushDepth();
}
~DepthTracker() {
_document->PopDepth();
}
private:
XMLDocument * _document;
};
void PushDepth();
void PopDepth();
template<class NodeType, int PoolElementSize>
NodeType* CreateUnlinkedNode( MemPoolT<PoolElementSize>& pool );
};

20
tinyxml2/test.vcxproj
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@@ -1,5 +1,5 @@
<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ItemGroup Label="ProjectConfigurations">
<ProjectConfiguration Include="Debug-Dll|Win32">
<Configuration>Debug-Dll</Configuration>
@@ -37,60 +37,60 @@
<PropertyGroup Label="Globals">
<ProjectGuid>{E8FB2712-8666-4662-A5B8-2B5B0FB1A260}</ProjectGuid>
<RootNamespace>test</RootNamespace>
<WindowsTargetPlatformVersion>8.1</WindowsTargetPlatformVersion>
<WindowsTargetPlatformVersion>10.0.16299.0</WindowsTargetPlatformVersion>
</PropertyGroup>
<Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Lib|Win32'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Lib|x64'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Dll|Win32'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Dll|x64'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Lib|Win32'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Lib|x64'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Dll|Win32'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Dll|x64'" Label="Configuration">
<ConfigurationType>Application</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Label="Configuration" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
<CharacterSet>Unicode</CharacterSet>

20
tinyxml2/tinyxml2.vcxproj
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@@ -1,5 +1,5 @@
<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ItemGroup Label="ProjectConfigurations">
<ProjectConfiguration Include="Debug-Dll|Win32">
<Configuration>Debug-Dll</Configuration>
@@ -38,60 +38,60 @@
<ProjectGuid>{D1C528B6-AA02-4D29-9D61-DC08E317A70D}</ProjectGuid>
<Keyword>Win32Proj</Keyword>
<RootNamespace>tinyxml2</RootNamespace>
<WindowsTargetPlatformVersion>8.1</WindowsTargetPlatformVersion>
<WindowsTargetPlatformVersion>10.0.16299.0</WindowsTargetPlatformVersion>
</PropertyGroup>
<Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Lib|Win32'" Label="Configuration">
<ConfigurationType>StaticLibrary</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Dll|Win32'" Label="Configuration">
<ConfigurationType>DynamicLibrary</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Lib|x64'" Label="Configuration">
<ConfigurationType>StaticLibrary</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug-Dll|x64'" Label="Configuration">
<ConfigurationType>DynamicLibrary</ConfigurationType>
<UseDebugLibraries>true</UseDebugLibraries>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Lib|Win32'" Label="Configuration">
<ConfigurationType>StaticLibrary</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Dll|Win32'" Label="Configuration">
<ConfigurationType>DynamicLibrary</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Lib|x64'" Label="Configuration">
<ConfigurationType>StaticLibrary</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release-Dll|x64'" Label="Configuration">
<ConfigurationType>DynamicLibrary</ConfigurationType>
<UseDebugLibraries>false</UseDebugLibraries>
<WholeProgramOptimization>true</WholeProgramOptimization>
<CharacterSet>Unicode</CharacterSet>
<PlatformToolset>v140</PlatformToolset>
<PlatformToolset>v141</PlatformToolset>
</PropertyGroup>
<PropertyGroup Label="Configuration" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
<ConfigurationType>StaticLibrary</ConfigurationType>

14
xmltest.cpp
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@@ -2025,6 +2025,20 @@ int main( int argc, const char ** argv )
}
}
{
// Bad bad crash. Parsing error results in stack overflow, if uncaught.
const char* TESTS[] = {
"./resources/xmltest-5330.xml",
"./resources/xmltest-4636783552757760.xml",
"./resources/xmltest-5720541257269248.xml",
0
};
for (int i=0; TESTS[i]; ++i) {
XMLDocument doc;
doc.LoadFile(TESTS[i]);
XMLTest("Stack overflow prevented.", XML_ELEMENT_DEPTH_EXCEEDED, doc.ErrorID());
}
}
{
// Crashing reported via email.
const char* xml =