evm/memory: fix javascript loop index overflow

cdump · Dec 23, 2023 · 0cd8ff3 · 0cd8ff3
1 parent 4241138
commit 0cd8ff3
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Showing 2 changed files with 4 additions and 4 deletions.
diff --git a/evmole/evm/memory.py b/evmole/evm/memory.py
@@ -13,8 +13,8 @@ def store(self, offset: int, value: bytes):
 
     def load(self, offset: int) -> tuple[bytes, set[bytes]]:
         res: list[tuple[int, bytes, bytes | None]] = [(0, b'\x00', None)] * 32
-        for i in range(offset, offset + 32):
-            idx = i - offset
+        for idx in range(32):
+            i = idx + offset
             for off, seq, val in self._data:
                 if seq >= res[idx][0] and i >= off and i < off + len(val):
                     res[idx] = (seq, val[i - off : i - off + 1], val)

diff --git a/js/src/evm/memory.js b/js/src/evm/memory.js
@@ -17,8 +17,8 @@ export default class Memory {
 
   load(offset) {
     const res = new Array(32).fill([0, 0, undefined])
-    for (let i = offset; i < offset + 32; i++) {
-      const idx = i - offset
+    for (let idx = 0; idx < 32; idx++) {
+      const i = idx + offset
       for (const [off, seq, val] of this._data) {
         if (seq >= res[idx][0] && i >= off && i < off + val.length) {
           res[idx] = [seq, val[i - off], val]