diff options
| -rw-r--r-- | Changelog.md | 2 | ||||
| -rw-r--r-- | libsolidity/codegen/ContractCompiler.cpp | 11 | ||||
| -rw-r--r-- | test/libsolidity/SolidityEndToEndTest.cpp | 19 |
3 files changed, 25 insertions, 7 deletions
diff --git a/Changelog.md b/Changelog.md index ed3cdfea..c9e76ee5 100644 --- a/Changelog.md +++ b/Changelog.md @@ -4,6 +4,8 @@ Features: * Code Generator: Always use all available gas for calls as experimental 0.5.0 feature (previously, some amount was retained in order to work in pre-tangerine whistle EVM versions) + * Code Generator: Do not accept data with less than four bytes (truncated function + signature) for regular function calls - fallback function is invoked instead. * Parser: Better error message for unexpected trailing comma in parameter lists. * Standard JSON: Support the ``outputSelection`` field for selective compilation of supplied sources. * Syntax Checker: Unary ``+`` is now a syntax error as experimental 0.5.0 feature. diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp index 429db532..74565ae4 100644 --- a/libsolidity/codegen/ContractCompiler.cpp +++ b/libsolidity/codegen/ContractCompiler.cpp @@ -251,13 +251,10 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac FunctionDefinition const* fallback = _contract.fallbackFunction(); eth::AssemblyItem notFound = m_context.newTag(); - // shortcut messages without data if we have many functions in order to be able to receive - // ether with constant gas - if (interfaceFunctions.size() > 5 || fallback) - { - m_context << Instruction::CALLDATASIZE << Instruction::ISZERO; - m_context.appendConditionalJumpTo(notFound); - } + // directly jump to fallback if the data is too short to contain a function selector + // also guards against short data + m_context << u256(4) << Instruction::CALLDATASIZE << Instruction::LT; + m_context.appendConditionalJumpTo(notFound); // retrieve the function signature hash from the calldata if (!interfaceFunctions.empty()) diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp index 648c13cb..9a837113 100644 --- a/test/libsolidity/SolidityEndToEndTest.cpp +++ b/test/libsolidity/SolidityEndToEndTest.cpp @@ -2899,6 +2899,25 @@ BOOST_AUTO_TEST_CASE(default_fallback_throws) ABI_CHECK(callContractFunction("f()"), encodeArgs(0)); } +BOOST_AUTO_TEST_CASE(short_data_calls_fallback) +{ + char const* sourceCode = R"( + contract A { + uint public x; + // Signature is d88e0b00 + function fow() { x = 3; } + function () { x = 2; } + } + )"; + compileAndRun(sourceCode); + // should call fallback + sendMessage(asBytes("\xd8\x8e\x0b"), false, 0); + ABI_CHECK(callContractFunction("x()"), encodeArgs(2)); + // should call function + sendMessage(asBytes(string("\xd8\x8e\x0b") + string(1, 0)), false, 0); + ABI_CHECK(callContractFunction("x()"), encodeArgs(3)); +} + BOOST_AUTO_TEST_CASE(event) { char const* sourceCode = R"( |