From b907b6b0b3ad1bedf61273d9ce38ced4c4748892 Mon Sep 17 00:00:00 2001 From: The3D Date: Wed, 30 Sep 2020 17:40:47 +0200 Subject: [PATCH 1/5] Initial fix --- contracts/libraries/helpers/Errors.sol | 4 +++- contracts/tokenization/AToken.sol | 9 ++++++--- contracts/tokenization/VariableDebtToken.sol | 12 ++++++++++-- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/contracts/libraries/helpers/Errors.sol b/contracts/libraries/helpers/Errors.sol index 48fc7f32..42d93a39 100644 --- a/contracts/libraries/helpers/Errors.sol +++ b/contracts/libraries/helpers/Errors.sol @@ -45,10 +45,12 @@ library Errors { string public constant INVALID_EQUAL_ASSETS_TO_SWAP = '56'; string public constant NO_MORE_RESERVES_ALLOWED = '59'; - // require error messages - aToken + // require error messages - aToken - DebtTokens string public constant CALLER_MUST_BE_LENDING_POOL = '28'; // 'The caller of this function must be a lending pool' string public constant CANNOT_GIVE_ALLOWANCE_TO_HIMSELF = '30'; // 'User cannot give allowance to himself' string public constant TRANSFER_AMOUNT_NOT_GT_0 = '31'; // 'Transferred amount needs to be greater than zero' + string public constant INVALID_MINT_AMOUNT = '53'; //invalid amount to mint + string public constant INVALID_BURN_AMOUNT = '53'; //invalid amount to burn // require error messages - ReserveLogic string public constant RESERVE_ALREADY_INITIALIZED = '34'; // 'Reserve has already been initialized' diff --git a/contracts/tokenization/AToken.sol b/contracts/tokenization/AToken.sol index 98c54bcd..8dcf669e 100644 --- a/contracts/tokenization/AToken.sol +++ b/contracts/tokenization/AToken.sol @@ -101,7 +101,9 @@ contract AToken is VersionedInitializable, IncentivizedERC20, IAToken { uint256 amount, uint256 index ) external override onlyLendingPool { - _burn(user, amount.rayDiv(index)); + uint256 amountScaled = amount.rayDiv(index); + require(amountScaled != 0, Errors.INVALID_BURN_AMOUNT); + _burn(user, amountScaled); //transfers the underlying to the target IERC20(UNDERLYING_ASSET_ADDRESS).safeTransfer(receiverOfUnderlying, amount); @@ -122,8 +124,9 @@ contract AToken is VersionedInitializable, IncentivizedERC20, IAToken { uint256 amount, uint256 index ) external override onlyLendingPool { - //mint an equivalent amount of tokens to cover the new deposit - _mint(user, amount.rayDiv(index)); + uint256 amountScaled = amount.rayDiv(index); + require(amountScaled != 0, Errors.INVALID_MINT_AMOUNT); + _mint(user, amountScaled); //transfer event to track balances emit Transfer(address(0), user, amount); diff --git a/contracts/tokenization/VariableDebtToken.sol b/contracts/tokenization/VariableDebtToken.sol index 5e0f2dff..e7bd7309 100644 --- a/contracts/tokenization/VariableDebtToken.sol +++ b/contracts/tokenization/VariableDebtToken.sol @@ -7,6 +7,7 @@ import {SafeMath} from '@openzeppelin/contracts/math/SafeMath.sol'; import {DebtTokenBase} from './base/DebtTokenBase.sol'; import {WadRayMath} from '../libraries/math/WadRayMath.sol'; import {IVariableDebtToken} from './interfaces/IVariableDebtToken.sol'; +import {Errors} from '../libraries/helpers/Errors.sol'; /** * @title contract VariableDebtToken @@ -60,7 +61,10 @@ contract VariableDebtToken is DebtTokenBase, IVariableDebtToken { uint256 index ) external override onlyLendingPool { - _mint(user, amount.rayDiv(index)); + uint256 amountScaled = amount.rayDiv(index); + require(amountScaled != 0, Errors.INVALID_MINT_AMOUNT); + + _mint(user, amountScaled); emit Transfer(address(0), user, amount); emit Mint(user, amount, index); @@ -76,7 +80,11 @@ contract VariableDebtToken is DebtTokenBase, IVariableDebtToken { uint256 amount, uint256 index ) external override onlyLendingPool { - _burn(user, amount.rayDiv(index)); + + uint256 amountScaled = amount.rayDiv(index); + require(amountScaled != 0, Errors.INVALID_BURN_AMOUNT); + + _burn(user, amountScaled); emit Transfer(user, address(0), amount); emit Burn(user, amount, index); From 758675c132ae74fb99b2bb293ecd193159d3fd91 Mon Sep 17 00:00:00 2001 From: The3D Date: Wed, 30 Sep 2020 17:59:47 +0200 Subject: [PATCH 2/5] Fixes tests --- .../LendingPoolCollateralManager.sol | 21 ++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/contracts/lendingpool/LendingPoolCollateralManager.sol b/contracts/lendingpool/LendingPoolCollateralManager.sol index 75f4f659..bfec17cd 100644 --- a/contracts/lendingpool/LendingPoolCollateralManager.sol +++ b/contracts/lendingpool/LendingPoolCollateralManager.sol @@ -238,12 +238,15 @@ contract LendingPoolCollateralManager is VersionedInitializable, LendingPoolStor principalReserve.variableBorrowIndex ); } else { - IVariableDebtToken(principalReserve.variableDebtTokenAddress).burn( - user, - vars.userVariableDebt, - principalReserve.variableBorrowIndex - ); - + //if the user does not have variable debt, no need to try to burn variable + //debt tokens + if (vars.userVariableDebt > 0) { + IVariableDebtToken(principalReserve.variableDebtTokenAddress).burn( + user, + vars.userVariableDebt, + principalReserve.variableBorrowIndex + ); + } IStableDebtToken(principalReserve.stableDebtTokenAddress).burn( user, vars.actualAmountToLiquidate.sub(vars.userVariableDebt) @@ -412,7 +415,11 @@ contract LendingPoolCollateralManager is VersionedInitializable, LendingPoolStor vars.actualAmountToLiquidate, 0 ); - IERC20(principal).safeTransferFrom(receiver, vars.principalAToken, vars.actualAmountToLiquidate); + IERC20(principal).safeTransferFrom( + receiver, + vars.principalAToken, + vars.actualAmountToLiquidate + ); if (vars.userVariableDebt >= vars.actualAmountToLiquidate) { IVariableDebtToken(debtReserve.variableDebtTokenAddress).burn( From 5a67250743ba42cc4a1097b0fffd828a9e17714e Mon Sep 17 00:00:00 2001 From: The3D Date: Wed, 30 Sep 2020 18:03:34 +0200 Subject: [PATCH 3/5] fixed error code --- contracts/libraries/helpers/Errors.sol | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/contracts/libraries/helpers/Errors.sol b/contracts/libraries/helpers/Errors.sol index 42d93a39..cf0923c7 100644 --- a/contracts/libraries/helpers/Errors.sol +++ b/contracts/libraries/helpers/Errors.sol @@ -50,7 +50,7 @@ library Errors { string public constant CANNOT_GIVE_ALLOWANCE_TO_HIMSELF = '30'; // 'User cannot give allowance to himself' string public constant TRANSFER_AMOUNT_NOT_GT_0 = '31'; // 'Transferred amount needs to be greater than zero' string public constant INVALID_MINT_AMOUNT = '53'; //invalid amount to mint - string public constant INVALID_BURN_AMOUNT = '53'; //invalid amount to burn + string public constant INVALID_BURN_AMOUNT = '54'; //invalid amount to burn // require error messages - ReserveLogic string public constant RESERVE_ALREADY_INITIALIZED = '34'; // 'Reserve has already been initialized' From c45d6c254bd66a2a29ac88e50ba850f926b9bd60 Mon Sep 17 00:00:00 2001 From: The3D Date: Mon, 5 Oct 2020 13:11:53 +0200 Subject: [PATCH 4/5] fixes #56 --- contracts/tokenization/AToken.sol | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/contracts/tokenization/AToken.sol b/contracts/tokenization/AToken.sol index 8dcf669e..4be67c12 100644 --- a/contracts/tokenization/AToken.sol +++ b/contracts/tokenization/AToken.sol @@ -134,7 +134,17 @@ contract AToken is VersionedInitializable, IncentivizedERC20, IAToken { } function mintToTreasury(uint256 amount, uint256 index) external override onlyLendingPool { - _mint(RESERVE_TREASURY_ADDRESS, amount.div(index)); + + if(amount == 0){ + return; + } + + //compared to the normal mint, we don't check for rounding errors. + //the amount to mint can easily be very small since is a fraction of the interest + //accrued. in that case, the treasury will experience a (very small) loss, but it + //wont cause potentially valid transactions to fail. + + _mint(RESERVE_TREASURY_ADDRESS, amount.rayDiv(index)); //transfer event to track balances emit Transfer(address(0), RESERVE_TREASURY_ADDRESS, amount); From 3ad9e7b9e01c4d639bc587ff32b8eb6820880cb3 Mon Sep 17 00:00:00 2001 From: The3D Date: Mon, 5 Oct 2020 13:12:58 +0200 Subject: [PATCH 5/5] Added natspec comment to mintToTreasury --- contracts/tokenization/AToken.sol | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/contracts/tokenization/AToken.sol b/contracts/tokenization/AToken.sol index 4be67c12..016a5601 100644 --- a/contracts/tokenization/AToken.sol +++ b/contracts/tokenization/AToken.sol @@ -118,6 +118,7 @@ contract AToken is VersionedInitializable, IncentivizedERC20, IAToken { * only lending pools can call this function * @param user the address receiving the minted tokens * @param amount the amount of tokens to mint + * @param index the the last index of the reserve */ function mint( address user, @@ -133,6 +134,13 @@ contract AToken is VersionedInitializable, IncentivizedERC20, IAToken { emit Mint(user, amount, index); } + + /** + * @dev mints aTokens to reserve treasury + * only lending pools can call this function + * @param amount the amount of tokens to mint to the treasury + * @param index the the last index of the reserve + */ function mintToTreasury(uint256 amount, uint256 index) external override onlyLendingPool { if(amount == 0){