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-rw-r--r--xfa/fxfa/fm2js/cxfa_fmparser.cpp74
-rw-r--r--xfa/fxfa/fm2js/cxfa_fmparser.h7
-rw-r--r--xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp7
3 files changed, 63 insertions, 25 deletions
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.cpp b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
index 4cd9a747a9..42a65e5838 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
@@ -14,12 +14,13 @@
namespace {
-const int kMaxAssignmentChainLength = 12;
+const unsigned int kMaxAssignmentChainLength = 12;
+const unsigned int kMaxParseDepth = 2000;
} // namespace
CXFA_FMParser::CXFA_FMParser(const CFX_WideStringC& wsFormcalc)
- : m_error(false) {
+ : m_error(false), m_parse_depth(0), m_max_parse_depth(kMaxParseDepth) {
m_lexer = pdfium::MakeUnique<CXFA_FMLexer>(wsFormcalc);
m_token = m_lexer->NextToken();
}
@@ -56,13 +57,18 @@ bool CXFA_FMParser::CheckThenNext(XFA_FM_TOKEN op) {
return NextToken();
}
+bool CXFA_FMParser::IncrementParseDepthAndCheck() {
+ return ++m_parse_depth < m_max_parse_depth;
+}
+
std::vector<std::unique_ptr<CXFA_FMExpression>>
CXFA_FMParser::ParseTopExpression() {
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
+ return std::vector<std::unique_ptr<CXFA_FMExpression>>();
+
std::unique_ptr<CXFA_FMExpression> expr;
std::vector<std::unique_ptr<CXFA_FMExpression>> expressions;
- if (HasError())
- return expressions;
-
while (!HasError()) {
if (m_token->m_type == TOKeof || m_token->m_type == TOKendfunc ||
m_token->m_type == TOKendif || m_token->m_type == TOKelseif ||
@@ -73,18 +79,16 @@ CXFA_FMParser::ParseTopExpression() {
expr = m_token->m_type == TOKfunc ? ParseFunction() : ParseExpression();
if (!expr) {
m_error = true;
- expressions.clear();
break;
}
expressions.push_back(std::move(expr));
}
- if (HasError())
- expressions.clear();
- return expressions;
+ return std::vector<std::unique_ptr<CXFA_FMExpression>>();
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseFunction() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
CFX_WideStringC ident;
@@ -146,7 +150,8 @@ std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseFunction() {
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
std::unique_ptr<CXFA_FMExpression> expr;
@@ -198,7 +203,8 @@ std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseExpression() {
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseVarExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
CFX_WideStringC ident;
@@ -254,7 +260,8 @@ CXFA_FMParser::ParseSimpleExpression() {
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseExpExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -266,7 +273,8 @@ std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseExpExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParseLogicalOrExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -300,7 +308,8 @@ CXFA_FMParser::ParseLogicalOrExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParseLogicalAndExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -333,7 +342,8 @@ CXFA_FMParser::ParseLogicalAndExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParseEqualityExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -377,7 +387,8 @@ CXFA_FMParser::ParseEqualityExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParseRelationalExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -446,7 +457,8 @@ CXFA_FMParser::ParseRelationalExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParseAddtiveExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -489,7 +501,8 @@ CXFA_FMParser::ParseAddtiveExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParseMultiplicativeExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -531,7 +544,8 @@ CXFA_FMParser::ParseMultiplicativeExpression() {
}
std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseUnaryExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
std::unique_ptr<CXFA_FMSimpleExpression> expr;
@@ -578,7 +592,8 @@ std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseUnaryExpression() {
std::unique_ptr<CXFA_FMSimpleExpression>
CXFA_FMParser::ParsePrimaryExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
std::unique_ptr<CXFA_FMSimpleExpression> expr;
@@ -661,6 +676,7 @@ std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParsePostExpression(
ParseSimpleExpression();
if (!simple_expr)
return nullptr;
+
expressions.push_back(std::move(simple_expr));
if (m_token->m_type == TOKcomma) {
if (!NextToken())
@@ -834,7 +850,8 @@ std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParsePostExpression(
}
std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseIndexExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -876,6 +893,10 @@ std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseIndexExpression() {
}
std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseParenExpression() {
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
+ return nullptr;
+
if (!CheckThenNext(TOKlparen))
return nullptr;
@@ -951,7 +972,8 @@ std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseBlockExpression() {
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseIfExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -1021,7 +1043,8 @@ std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseIfExpression() {
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseWhileExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
uint32_t line = m_token->m_line_num;
@@ -1055,7 +1078,8 @@ CXFA_FMParser::ParseSubassignmentInForExpression() {
}
std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseForExpression() {
- if (HasError())
+ CFX_AutoRestorer<unsigned long> restorer(&m_parse_depth);
+ if (HasError() || !IncrementParseDepthAndCheck())
return nullptr;
CFX_WideStringC wsVariant;
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.h b/xfa/fxfa/fm2js/cxfa_fmparser.h
index 66eb1f8392..ddfaa1aaa6 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser.h
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.h
@@ -21,9 +21,14 @@ class CXFA_FMParser {
std::unique_ptr<CXFA_FMFunctionDefinition> Parse();
bool HasError() const;
+ void SetMaxParseDepthForTest(unsigned long max_depth) {
+ m_max_parse_depth = max_depth;
+ }
+
private:
bool NextToken();
bool CheckThenNext(XFA_FM_TOKEN op);
+ bool IncrementParseDepthAndCheck();
std::vector<std::unique_ptr<CXFA_FMExpression>> ParseTopExpression();
std::unique_ptr<CXFA_FMExpression> ParseFunction();
@@ -54,6 +59,8 @@ class CXFA_FMParser {
std::unique_ptr<CXFA_FMLexer> m_lexer;
std::unique_ptr<CXFA_FMToken> m_token;
bool m_error;
+ unsigned long m_parse_depth;
+ unsigned long m_max_parse_depth;
};
#endif // XFA_FXFA_FM2JS_CXFA_FMPARSER_H_
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp b/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp
index 9907890e83..214fd4aec3 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmparser_unittest.cpp
@@ -107,3 +107,10 @@ TEST(CXFA_FMParserTest, Parse) {
EXPECT_TRUE(ast->ToJavaScript(buf));
EXPECT_EQ(ret, buf.AsStringC());
}
+
+TEST(CXFA_FMParserTest, MaxParseDepth) {
+ auto parser = pdfium::MakeUnique<CXFA_FMParser>(L"foo(bar[baz(fizz[0])])");
+ parser->SetMaxParseDepthForTest(5);
+ EXPECT_EQ(nullptr, parser->Parse());
+ EXPECT_TRUE(parser->HasError());
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-03 14:50:07 +0000