From 391841190c8bac55215fa01e1a376c16f4814d1e Mon Sep 17 00:00:00 2001
From: The3D <frangellaemilio@gmail.com>
Date: Tue, 22 Mar 2022 13:56:18 +0100
Subject: [PATCH] fix: fixes reentrancy issue on LendingPoolCollateralManager

---
 .../LendingPoolCollateralManager.sol          | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/contracts/protocol/lendingpool/LendingPoolCollateralManager.sol b/contracts/protocol/lendingpool/LendingPoolCollateralManager.sol
index 80692726..c6a6f2d3 100644
--- a/contracts/protocol/lendingpool/LendingPoolCollateralManager.sol
+++ b/contracts/protocol/lendingpool/LendingPoolCollateralManager.sol
@@ -150,8 +150,9 @@ contract LendingPoolCollateralManager is
     // If the liquidator reclaims the underlying asset, we make sure there is enough available liquidity in the
     // collateral reserve
     if (!receiveAToken) {
-      uint256 currentAvailableCollateral =
-        IERC20(collateralAsset).balanceOf(address(vars.collateralAtoken));
+      uint256 currentAvailableCollateral = IERC20(collateralAsset).balanceOf(
+        address(vars.collateralAtoken)
+      );
       if (currentAvailableCollateral < vars.maxCollateralToLiquidate) {
         return (
           uint256(Errors.CollateralManagerErrors.NOT_ENOUGH_LIQUIDITY),
@@ -190,6 +191,13 @@ contract LendingPoolCollateralManager is
       0
     );
 
+    // If the collateral being liquidated is equal to the user balance,
+    // we set the currency as not being used as collateral anymore
+    if (vars.maxCollateralToLiquidate == vars.userCollateralBalance) {
+      userConfig.setUsingAsCollateral(collateralReserve.id, false);
+      emit ReserveUsedAsCollateralDisabled(collateralAsset, user);
+    }
+
     if (receiveAToken) {
       vars.liquidatorPreviousATokenBalance = IERC20(vars.collateralAtoken).balanceOf(msg.sender);
       vars.collateralAtoken.transferOnLiquidation(user, msg.sender, vars.maxCollateralToLiquidate);
@@ -217,13 +225,6 @@ contract LendingPoolCollateralManager is
       );
     }
 
-    // If the collateral being liquidated is equal to the user balance,
-    // we set the currency as not being used as collateral anymore
-    if (vars.maxCollateralToLiquidate == vars.userCollateralBalance) {
-      userConfig.setUsingAsCollateral(collateralReserve.id, false);
-      emit ReserveUsedAsCollateralDisabled(collateralAsset, user);
-    }
-
     // Transfers the debt asset being repaid to the aToken, where the liquidity is kept
     IERC20(debtAsset).safeTransferFrom(
       msg.sender,