🩹 (aave-3) Don't repay too much on liquidation #1073

morpho-org · Jul 11, 2022 · 125c654 · 125c654
1 parent 31b2dda
commit 125c654
Show file tree

Hide file tree

Showing 2 changed files with 34 additions and 14 deletions.
diff --git a/contracts/aave-v2/ExitPositionsManager.sol b/contracts/aave-v2/ExitPositionsManager.sol
@@ -217,15 +217,25 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
             vars.borrowedTokenUnit = 10**vars.borrowedReserveDecimals;
         }
 
-        uint256 amountToSeize = Math.min(
-            ((amountToLiquidate *
-                oracle.getAssetPrice(tokenBorrowedAddress) *
-                vars.collateralTokenUnit) /
-                (vars.borrowedTokenUnit * oracle.getAssetPrice(tokenCollateralAddress)))
-            .percentMul(vars.liquidationBonus), // Same mechanism as Aave.
-            _getUserSupplyBalanceInOf(_poolTokenCollateralAddress, _borrower)
+        uint256 borrowedTokenPrice = oracle.getAssetPrice(tokenBorrowedAddress);
+        uint256 collateralPrice = oracle.getAssetPrice(tokenCollateralAddress);
+        uint256 amountToSeize = ((amountToLiquidate *
+            borrowedTokenPrice *
+            vars.collateralTokenUnit) / (vars.borrowedTokenUnit * collateralPrice))
+        .percentMul(vars.liquidationBonus);
+
+        uint256 collateralBalance = _getUserSupplyBalanceInOf(
+            _poolTokenCollateralAddress,
+            _borrower
         );
 
+        if (amountToSeize > collateralBalance) {
+            amountToSeize = collateralBalance;
+            amountToLiquidate = ((collateralBalance * collateralPrice * vars.borrowedTokenUnit) /
+                (borrowedTokenPrice * vars.collateralTokenUnit))
+            .percentDiv(vars.liquidationBonus);
+        }
+
         _safeRepayLogic(_poolTokenBorrowedAddress, msg.sender, _borrower, amountToLiquidate, 0);
         _safeWithdrawLogic(_poolTokenCollateralAddress, amountToSeize, _borrower, msg.sender, 0);
 

diff --git a/contracts/aave-v3/ExitPositionsManager.sol b/contracts/aave-v3/ExitPositionsManager.sol
@@ -216,15 +216,25 @@ contract ExitPositionsManager is IExitPositionsManager, PositionsManagerUtils {
             vars.borrowedTokenUnit = 10**vars.borrowedReserveDecimals;
         }
 
-        uint256 amountToSeize = Math.min(
-            ((amountToLiquidate *
-                oracle.getAssetPrice(tokenBorrowedAddress) *
-                vars.collateralTokenUnit) /
-                (vars.borrowedTokenUnit * oracle.getAssetPrice(tokenCollateralAddress)))
-            .percentMul(vars.liquidationBonus), // Same mechanism as Aave.
-            _getUserSupplyBalanceInOf(_poolTokenCollateralAddress, _borrower)
+        uint256 borrowedTokenPrice = oracle.getAssetPrice(tokenBorrowedAddress);
+        uint256 collateralPrice = oracle.getAssetPrice(tokenCollateralAddress);
+        uint256 amountToSeize = ((amountToLiquidate *
+            borrowedTokenPrice *
+            vars.collateralTokenUnit) / (vars.borrowedTokenUnit * collateralPrice))
+        .percentMul(vars.liquidationBonus);
+
+        uint256 collateralBalance = _getUserSupplyBalanceInOf(
+            _poolTokenCollateralAddress,
+            _borrower
         );
 
+        if (amountToSeize > collateralBalance) {
+            amountToSeize = collateralBalance;
+            amountToLiquidate = ((collateralBalance * collateralPrice * vars.borrowedTokenUnit) /
+                (borrowedTokenPrice * vars.collateralTokenUnit))
+            .percentDiv(vars.liquidationBonus);
+        }
+
         _safeRepayLogic(_poolTokenBorrowedAddress, msg.sender, _borrower, amountToLiquidate, 0);
         _safeWithdrawLogic(_poolTokenCollateralAddress, amountToSeize, _borrower, msg.sender, 0);