Sherlock 92: startClaimableReserveAuction using old inflator (#587)

* Sherlock 92: startClaimableReserveAuction using old inflator * Add test to show interest accrued when start reserve auction
ajna-finance · Feb 11, 2023 · 1414435 · 1414435
1 parent d45aec9
commit 1414435
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Showing 4 changed files with 60 additions and 7 deletions.
diff --git a/src/base/Pool.sol b/src/base/Pool.sol
@@ -350,15 +350,16 @@ abstract contract Pool is Clone, ReentrancyGuard, Multicall, IPool {
             revert ReserveAuctionTooSoon();
         }
 
+        PoolState memory poolState = _accruePoolInterest();
+
         // start a new claimable reserve auction, passing in relevant parameters such as the current pool size, debt, balance, and inflator value
         uint256 kickerAward = Auctions.startClaimableReserveAuction(
             auctions,
             reserveAuction,
             StartReserveAuctionParams({
-                poolSize:    Deposits.treeSum(deposits),
-                t0PoolDebt:  poolBalances.t0Debt,
                 poolBalance: _getNormalizedPoolQuoteTokenBalance(),
-                inflator:    inflatorState.inflator
+                poolDebt:    poolState.debt,
+                poolSize:    Deposits.treeSum(deposits)
             })
         );
 
@@ -368,6 +369,9 @@ abstract contract Pool is Clone, ReentrancyGuard, Multicall, IPool {
         reserveAuction.latestBurnEventEpoch = latestBurnEpoch;
         reserveAuction.burnEvents[latestBurnEpoch].timestamp = block.timestamp;
 
+        // update pool interest rate state
+        _updateInterestState(poolState, _lup(poolState.debt));
+
         // transfer kicker award to msg.sender
         _transferQuoteToken(msg.sender, kickerAward);
     }

diff --git a/src/interfaces/pool/commons/IPoolReserveAuctionActions.sol b/src/interfaces/pool/commons/IPoolReserveAuctionActions.sol
@@ -26,8 +26,7 @@ interface IPoolReserveAuctionActions {
 /*********************/
 
 struct StartReserveAuctionParams {
-    uint256 poolSize;    // [WAD] total deposits in pool (with accrued debt)
-    uint256 t0PoolDebt;  // [WAD] current t0 pool debt
     uint256 poolBalance; // [WAD] pool quote token balance
-    uint256 inflator;    // [WAD] pool current inflator
+    uint256 poolDebt;    // [WAD] current pool debt
+    uint256 poolSize;    // [WAD] total deposits in pool (with accrued debt)
 }
diff --git a/src/libraries/external/Auctions.sol b/src/libraries/external/Auctions.sol
@@ -620,7 +620,7 @@ library Auctions {
         uint256 curUnclaimedAuctionReserve = reserveAuction_.unclaimed;
 
         uint256 claimable = _claimableReserves(
-            Maths.wmul(params_.t0PoolDebt, params_.inflator),
+            params_.poolDebt,
             params_.poolSize,
             auctions_.totalBondEscrowed,
             curUnclaimedAuctionReserve,

diff --git a/tests/forge/ERC20Pool/ERC20PoolReserveAuction.t.sol b/tests/forge/ERC20Pool/ERC20PoolReserveAuction.t.sol
@@ -19,17 +19,20 @@ contract ERC20PoolReserveAuctionTest is ERC20HelperContract {
     ERC20 AJNA = ERC20(_ajna);
 
     address internal _borrower;
+    address internal _borrower2;
     address internal _lender;
     address internal _bidder;
 
     function setUp() external {
         _pool      = ERC20Pool(new ERC20PoolFactory(address(AJNA)).deployPool(address(WBTC), address(USDC), 0.05 * 10**18));
 
         _borrower  = makeAddr("borrower");
+        _borrower2 = makeAddr("borrower2");
         _lender    = makeAddr("lender");
         _bidder    = makeAddr("bidder");
 
         deal(address(WBTC), _borrower, 10 * 1e8);
+        deal(address(WBTC), _borrower2, 10 * 1e8);
         deal(address(USDC), _borrower, 100 * 1e6);
 
         deal(address(USDC), _lender,   10_000 * 1e6);
@@ -40,6 +43,9 @@ contract ERC20PoolReserveAuctionTest is ERC20HelperContract {
         WBTC.approve(address(_pool), 10 * 1e18);
         USDC.approve(address(_pool), 1_000 * 1e18);
 
+        changePrank(_borrower2);
+        WBTC.approve(address(_pool), 10 * 1e18);
+
         changePrank(_bidder);
         AJNA.approve(address(_pool), 10 * 1e18);
 
@@ -112,4 +118,48 @@ contract ERC20PoolReserveAuctionTest is ERC20HelperContract {
         assertEq(USDC.balanceOf(address(_bidder)), 1.297968 * 1e6);
         assertEq(AJNA.balanceOf(address(_bidder)), 9.999999998885449254 * 1e18);
     }
+
+    function testReserveAuctionAccrueInterest() external {
+        _drawDebtNoLupCheck({
+            from:               _borrower2,
+            borrower:           _borrower2,
+            amountToBorrow:     300 * 1e18,
+            limitIndex:         7000,
+            collateralToPledge: 1 * 1e18
+        });
+
+        skip(26 weeks);
+
+        // repay entire debt
+        _repayDebtNoLupCheck({
+            from:             _borrower,
+            borrower:         _borrower,
+            amountToRepay:    400 * 1e18,
+            amountRepaid:     307.869212479869665749 * 1e18,
+            collateralToPull: 0
+        });
+
+        uint256 reservesWithoutNewInterest = 0.705309714116053616 * 1e18;
+        uint256 reservesWithNewInterest    = 1.789580885547436858 * 1e18;
+
+        uint256 snapshot = vm.snapshot();
+
+        // kick off a new auction without new interest accrued
+        _startClaimableReserveAuction({
+            from:              _bidder,
+            remainingReserves: reservesWithoutNewInterest,
+            price:             1000000000 * 1e18
+        });
+
+        vm.revertTo(snapshot);
+
+        skip(26 weeks);
+
+        // kick off a new auction with 26 weeks interest accrued
+        _startClaimableReserveAuction({
+            from:              _bidder,
+            remainingReserves: reservesWithNewInterest,
+            price:             1000000000 * 1e18
+        });
+    }
 }