routerBalances[msg.sender][_local] can be inflated in repayAavePortal due to underflow in unchecked math

Lines of code Vulnerability details function repayAavePortal address local, uint256 backingAmount, uint256 feeAmount, uint256 maxIn, bytes32 transferId external uint256 totalAmount = backingAmount + feeAmount; // in adopted uint256 routerBalance = s.routerBalancesmsg.senderlocal; // in local //...