explicitly check for swap amounts being too large (instead of depending on checked arithmetic overflows)

Author: hoytech

src/EulerSwap.sol

@@ -51,6 +51,7 @@ contract EulerSwap is IEulerSwap, EVCUtil {
     error Locked();
     error Overflow();
     error BadParam();
+    error AmountTooBig();
     error DifferentEVC();
     error AssetsOutOfOrderOrEqual();
     error CurveViolation();
@@ -105,6 +106,8 @@ contract EulerSwap is IEulerSwap, EVCUtil {
         callThroughEVC
         nonReentrant
     {
+        require(amount0Out <= type(uint112).max && amount1Out <= type(uint112).max, AmountTooBig());
+
         // Optimistically send tokens
 
         if (amount0Out > 0) withdrawAssets(vault0, amount0Out, to);

test/Limits.t.sol

@@ -107,4 +107,12 @@ contract LimitsTest is EulerSwapTestBase {
         assertEq(inLimit, type(uint112).max - 110e18);
         assertEq(outLimit, 18.5e18); // 10 in balance, plus 8.5 borrow cap
     }
+
+    function test_amountTooBig() public monotonicHolderNAV {
+        vm.expectRevert(EulerSwap.AmountTooBig.selector);
+        eulerSwap.swap(type(uint256).max, 0, address(this), "");
+
+        vm.expectRevert(EulerSwap.AmountTooBig.selector);
+        eulerSwap.swap(0, type(uint256).max, address(this), "");
+    }
 }