veRWA - klau5's results

Assign a value to a variable that already has the same value stored

Impact

Assign a value to a variable that already has the same value stored

Proof of Concept

In the _checkpoint_lender function, the lastUserBalance is already stored in lendingMarketBalances[_market][_lender][lastUserUpdateEpoch].

Since i in the for-loop starts from lastUserUpdateEpoch, lendingMarketBalances[_market][_lender][i] = lastUserBalance; meas lendingMarketBalances[_market][_lender][lastUserUpdateEpoch] = lastUserBalance;

This is meaningless because it’s trying to store the same value as the already stored value.

uint256 lastUserBalance = lendingMarketBalances[_market][_lender][lastUserUpdateEpoch];
for (uint256 i = lastUserUpdateEpoch; i <= updateUntilEpoch; i += WEEK) {
    lendingMarketBalances[_market][_lender][i] = lastUserBalance;
}

https://github.com/code-423n4/2023-08-verwa/blob/498a3004d577c8c5d0c71bff99ea3a7907b5ec23/src/LendingLedger.sol#L70-L73

Same issue happens at _checkpoint_market function.

uint256 lastMarketBalance = lendingMarketTotalBalance[_market][lastMarketUpdateEpoch];
for (uint256 i = lastMarketUpdateEpoch; i <= updateUntilEpoch; i += WEEK) {
    lendingMarketTotalBalance[_market][i] = lastMarketBalance;
}

https://github.com/code-423n4/2023-08-verwa/blob/498a3004d577c8c5d0c71bff99ea3a7907b5ec23/src/LendingLedger.sol#L91-L94

Tools Used

vscode

Recommended Mitigation Steps

Add WEEK when initializing i

• for (uint256 i = lastUserUpdateEpoch; i <= updateUntilEpoch; i += WEEK) { → for (uint256 i = lastUserUpdateEpoch + WEEK; i <= updateUntilEpoch; i += WEEK) {
• for (uint256 i = lastMarketUpdateEpoch; i <= updateUntilEpoch; i += WEEK) { → for (uint256 i = lastMarketUpdateEpoch + WEEK; i <= updateUntilEpoch; i += WEEK) {