[KSA-01C] Ineffectual Usage of Safe Arithmetics

[qcuong98]

KSA-01C: Ineffectual Usage of Safe Arithmetics

Type	Severity	Location
Language Specific		KSAggregationRouterV3.sol: • I-1: L93 • I-2: L335

Description:

The linked mathematical operation is guaranteed to be performed safely by logical inference, such as surrounding conditionals evaluated in require checks or if-else constructs.

Example:

uint256 gasBefore = gasleft();

if (block.timestamp > params.deadline) {
  revert DeadlinePassed(params.deadline, block.timestamp);
}

uint256[] memory inputBalances = _recordInputBalances(params.inputTokens);
uint256[] memory outputBalances =
  _recordOutputBalances(params.outputTokens, params.outputData, params.recipient);
uint256 nativeBalanceBefore = address(this).balance - msg.value;

_callPermit2(params.permit2Data);
_collectInputTokens(params.inputTokens, params.inputAmounts, params.inputData);

_callExecutor(params.executor, address(this).balance - nativeBalanceBefore, params.executorData);

outputAmounts =
  _processOutputTokens(params.outputTokens, params.outputData, outputBalances, params.recipient);
_refundInputTokens(params.inputTokens, inputBalances, params.recipient);

emit Swap(
  msg.sender,
  params.executor,
  params.recipient,
  params.inputTokens,
  params.inputAmounts,
  params.outputTokens,
  outputAmounts
);

emit ClientData(params.clientData);

gasUsed = gasBefore - gasleft();

Recommendation:

Given that safe arithmetics are toggled on by default in pragma versions of 0.8.X, we advise the linked statement to be wrapped in an unchecked code block thereby optimizing its execution cost.

[qcuong98]

Fixed