From 064d3d8e1582a10ba8bfb394750e0bdf06ba704c Mon Sep 17 00:00:00 2001
From: GregTheDev <mapler98@gmail.com>
Date: Wed, 3 Jan 2024 07:53:19 -0700
Subject: [PATCH] v1 borrower enforcer underflow

---
 src/enforcers/AstariaV1BorrowerEnforcer.sol | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/enforcers/AstariaV1BorrowerEnforcer.sol b/src/enforcers/AstariaV1BorrowerEnforcer.sol
index ecded5f..eabe314 100644
--- a/src/enforcers/AstariaV1BorrowerEnforcer.sol
+++ b/src/enforcers/AstariaV1BorrowerEnforcer.sol
@@ -120,19 +120,18 @@ contract AstariaV1BorrowerEnforcer is BorrowerEnforcer {
 
         // Will revert if startTime > endTime
         uint256 duration = v1Details.endTime - v1Details.startTime;
-        uint256 elapsed;
+        uint256 elapsed = block.timestamp - v1Details.startTime;
         uint256 remaining;
-        unchecked {
-            // block.timestamp <= endTime && startTime < endTime, can't overflow
-            elapsed = block.timestamp - v1Details.startTime;
+        assembly ("memory-safe") {
             // block.timestamp <= endTime, can't underflow
-            remaining = duration - elapsed;
+            remaining := sub(duration, elapsed)
         }
 
         // Calculate rate with a linear growth
         // Weight startRate by the remaining time, and endRate by the elapsed time
         uint256 totalBeforeDivision = (v1Details.startRate * remaining) + (endRate * elapsed);
         assembly ("memory-safe") {
+            // duration > 0, as startTime != endTime and endTime - startTime did not underflow
             currentRate := div(totalBeforeDivision, duration)
         }
     }