Submission Details
Severity:
wrong return values in the burn operation
When a user wants to withdraw tokens from the protocol they call the withdraw function when withdrawalsPaused not set to false.
function withdraw(uint256 amount) external nonReentrant whenNotPaused onlyValidAmount(amount) {
if (withdrawalsPaused) revert WithdrawalsArePaused();
// Update the reserve state before the withdrawal
ReserveLibrary.updateReserveState(reserve, rateData);
// Ensure sufficient liquidity is available
_ensureLiquidity(amount);
// Perform the withdrawal through ReserveLibrary
(uint256 amountWithdrawn, uint256 amountScaled, uint256 amountUnderlying) = ReserveLibrary.withdraw(
reserve, // ReserveData storage
rateData, // ReserveRateData storage
amount, // Amount to withdraw
msg.sender // Recipient
);
// Rebalance liquidity after withdrawal
_rebalanceLiquidity();
emit Withdraw(msg.sender, amountWithdrawn);
}
The function above calls to the internal withdraw which calls to the burn function
function withdraw(
ReserveData storage reserve,
ReserveRateData storage rateData,
uint256 amount,
address recipient
) internal returns (uint256 amountWithdrawn, uint256 amountScaled, uint256 amountUnderlying) {
if (amount < 1) revert InvalidAmount();
// Update the reserve interests
updateReserveInterests(reserve, rateData);
// Burn RToken from the recipient - will send underlying asset to the recipient
(uint256 burnedScaledAmount, uint256 newTotalSupply, uint256 amountUnderlying) = IRToken(reserve.reserveRTokenAddress).burn(
recipient, // from
recipient, // receiverOfUnderlying
amount, // amount
reserve.liquidityIndex // index
);
amountWithdrawn = burnedScaledAmount;
// Update the total liquidity and interest rates
updateInterestRatesAndLiquidity(reserve, rateData, 0, amountUnderlying);
emit Withdraw(recipient, amountUnderlying, burnedScaledAmount);
return (amountUnderlying, burnedScaledAmount, amountUnderlying);
}
From our current return values
(uint256 burnedScaledAmount, uint256 newTotalSupply, uint256 amountUnderlying) = IRToken(reserve.reserveRTokenAddress).burn(
recipient, // from
recipient, // receiverOfUnderlying
amount, // amount
reserve.liquidityIndex // index
);
looking at our burn here is what it currently returns
return (amount, totalSupply(), amount);
Amount which is the amountUnderlying is returned twice
Impact
Incorrect computations
Recommendation
Return the correct values as expected to avoid wrong return values
Updates
Lead Judging Commences
inallhonesty 3 months ago
Submission Judgement Published Assigned finding tags:
RToken::burn returns incorrect underlying asset amount (amount instead of amountScaled), leading to wrong interest rate calculations
inallhonesty 3 months ago
Submission Judgement Published Assigned finding tags:
RToken::burn returns incorrect underlying asset amount (amount instead of amountScaled), leading to wrong interest rate calculations
Prize pool breakdown
Total prize
77,280 USDC
nSLOC
3,86420 USDC / LOC
74,000
3,280
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