Fix false positive caused by early termination due to nested expressi…

…ons.
CNFS-Tech · Mar 26, 2021 · f3f1ccc · f3f1ccc
1 parent d75a132
commit f3f1ccc
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Showing 4 changed files with 19 additions and 11 deletions.
diff --git a/test/tools/ossfuzz/strictasm_diff_ossfuzz.cpp b/test/tools/ossfuzz/strictasm_diff_ossfuzz.cpp
@@ -86,7 +86,7 @@ extern "C" int LLVMFuzzerTestOneInput(uint8_t const* _data, size_t _size)
 		stack.parserResult()->code,
 		EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion())
 	);
-	if (termReason == yulFuzzerUtil::TerminationReason::StepLimitReached)
+	if (yulFuzzerUtil::resourceLimitsExceeded(termReason))
 		return 0;
 
 	stack.optimize();
@@ -97,6 +97,9 @@ extern "C" int LLVMFuzzerTestOneInput(uint8_t const* _data, size_t _size)
 		(yul::test::yul_fuzzer::yulFuzzerUtil::maxSteps * 4)
 	);
 
+	if (yulFuzzerUtil::resourceLimitsExceeded(termReason))
+		return 0;
+
 	bool isTraceEq = (os1.str() == os2.str());
 	yulAssert(isTraceEq, "Interpreted traces for optimized and unoptimized code differ.");
 	return 0;

diff --git a/test/tools/ossfuzz/yulFuzzerCommon.cpp b/test/tools/ossfuzz/yulFuzzerCommon.cpp
@@ -73,3 +73,11 @@ yulFuzzerUtil::TerminationReason yulFuzzerUtil::interpret(
 	state.dumpTraceAndState(_os);
 	return reason;
 }
+
+bool yulFuzzerUtil::resourceLimitsExceeded(TerminationReason _reason)
+{
+	return
+		_reason == yulFuzzerUtil::TerminationReason::StepLimitReached ||
+		_reason == yulFuzzerUtil::TerminationReason::TraceLimitReached ||
+		_reason == yulFuzzerUtil::TerminationReason::ExpresionNestingLimitReached;
+}
diff --git a/test/tools/ossfuzz/yulFuzzerCommon.h b/test/tools/ossfuzz/yulFuzzerCommon.h
@@ -40,6 +40,11 @@ struct yulFuzzerUtil
 		size_t _maxTraceSize = maxTraceSize,
 		size_t _maxExprNesting = maxExprNesting
 	);
+
+	/// @returns true if @param _reason for Yul interpreter terminating is
+	/// resource exhaustion of some form e.g., exceeded maximum time-out
+	/// threshold, number of nested expressions etc.
+	static bool resourceLimitsExceeded(TerminationReason _reason);
 	static size_t constexpr maxSteps = 100;
 	static size_t constexpr maxTraceSize = 75;
 	static size_t constexpr maxExprNesting = 64;

diff --git a/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp b/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
@@ -100,11 +100,7 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 		EVMDialect::strictAssemblyForEVMObjects(version)
 	);
 
-	if (
-		termReason == yulFuzzerUtil::TerminationReason::StepLimitReached ||
-		termReason == yulFuzzerUtil::TerminationReason::TraceLimitReached ||
-		termReason == yulFuzzerUtil::TerminationReason::ExpresionNestingLimitReached
-	)
+	if (yulFuzzerUtil::resourceLimitsExceeded(termReason))
 		return;
 
 	YulOptimizerTestCommon optimizerTest(
@@ -119,11 +115,7 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 		astBlock,
 		EVMDialect::strictAssemblyForEVMObjects(version)
 	);
-	if (
-		termReason == yulFuzzerUtil::TerminationReason::StepLimitReached ||
-		termReason == yulFuzzerUtil::TerminationReason::TraceLimitReached ||
-		termReason == yulFuzzerUtil::TerminationReason::ExpresionNestingLimitReached
-	)
+	if (yulFuzzerUtil::resourceLimitsExceeded(termReason))
 		return;
 
 	bool isTraceEq = (os1.str() == os2.str());