Gas: XDEFIDistribution.sol's withdrawAmount substraction can be unchecked

[code423n4]

Handle

Dravee

Vulnerability details

Impact

Waste of gas due to unnecessary underflow checks

Proof of Concept

On XDEFIDistribution.sol:120 and XDEFIDistribution.sol:175, you can find the following substraction:
uint256 withdrawAmount = amountUnlocked_ - lockAmount_;

However, as the Solidity version is 0.8.10, default overflow and underflow checks are made, which cost some gas.

You can save this gas with the unchecked keyword to bypass these checks as 5 lines above (L115 and L170), a require statement already checks that lockAmount_ <= amountUnlocked_.

Therefore, no underflow is possible.

Tools Used

VS Code

Recommended Mitigation Steps

Use the "unchecked" keyword

[deluca-mike]

Yep, while I originally did not want to messy the code with unchecked math, enough people have mentioned it, and I've now down enough analysis to just go ahead and do it.

[deluca-mike]

In release candidate contacts, done in _relock.