Stader Labs - Tomio's results

Title: empty constructor

Proof of Concept: NodeELRewardVault.sol#L14

Recommended Mitigation Steps: Remove if unused for gas saving

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Title: Using msg.sender directly is more effective

Proof of Concept: OperatorRewardsCollector.sol#L47 SDCollateral.sol#L44 SDCollateral.sol#L59

Recommended Mitigation Steps: delete operator and use msg.sender directly instead of caching it.

	uint256 amount = balances[msg.sender];
        balances[msg.sender] -= amount;

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Title: function getTotalQueuedValidatorCount() gas improvement on returning value

Proof of Concept: PermissionedNodeRegistry.sol#L487

Recommended Mitigation Steps: by set totalQueuedValidators in returns L#486 and delete L#487 can save gas

function getTotalQueuedValidatorCount() external view override returns (uint256 totalQueuedValidators) { //@audit-info: set here

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Title: function getOperatorTotalNonTerminalKeys() gas improvement on returning value

Proof of Concept: PermissionedNodeRegistry.sol#L533

Recommended Mitigation Steps: by set totalNonWithdrawnKeyCount in returns L#526 and delete L#533 can save gas

function getOperatorTotalNonTerminalKeys(
        address _nodeOperator,
        uint256 _startIndex,
        uint256 _endIndex
    ) public view override returns (uint64 totalNonWithdrawnKeyCount) { //@audit-info: set here

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Title: Avoid unnecessary memory allocation and copy

Proof of Concept: PermissionlessPool.sol#L276-L286

Recommended Mitigation Steps: instead of allocating a new bytes array and copying the values one by one, you can use abi.encodePacked to directly pack the values into a bytes array.

Consider change it to:

function to_little_endian_64(uint256 _depositAmount) internal pure returns (bytes memory) {
    uint64 value = uint64(_depositAmount / 1 gwei);
    return abi.encodePacked(value);
}

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Title: Avoid unnecessary variable assignments

Proof of Concept: PoolUtils.sol#L256-L257

Recommended Mitigation Steps: Instead of assigning usersETH and collateralETH to variables, use it directly.

Consider change it to:

function calculateRewardShare(uint8 _poolId, uint256 _totalRewards)
    external
    view
    override
    returns (
        uint256 userShare,
        uint256 operatorShare,
        uint256 protocolShare
    )
{
    uint256 TOTAL_STAKED_ETH = staderConfig.getStakedEthPerNode();
    uint256 protocolFeeBps = getProtocolFee(_poolId);
    uint256 operatorFeeBps = getOperatorFee(_poolId);

    uint256 _userShareBeforeCommission = (_totalRewards * (TOTAL_STAKED_ETH - getCollateralETH(_poolId))) / TOTAL_STAKED_ETH; //@audit-info: set here

    protocolShare = (protocolFeeBps * _userShareBeforeCommission) / staderConfig.getTotalFee();

    operatorShare = (_totalRewards * getCollateralETH(_poolId)) / TOTAL_STAKED_ETH; //@audit-info: set here
    operatorShare += (operatorFeeBps * _userShareBeforeCommission) / staderConfig.getTotalFee();

    userShare = _totalRewards - protocolShare - operatorShare;
}

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