Merge pull request #398 from ethereum/fix-copyslice-exception

Expr: fix downcast exception in simplify
ethereum · Oct 2, 2023 · 4e4bc8d · 4e4bc8d
2 parents e22d757 + 4f3345c
commit 4e4bc8d
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/src/EVM/Expr.hs b/src/EVM/Expr.hs
@@ -788,8 +788,11 @@ simplify e = if (mapExpr go e == e)
         -- n+sz of ConcreteBuf will be used by CopySlice
         (WriteWord wOff value (ConcreteBuf buf)) dst)
           -- Let's not deal with overflow
-          | n+sz >= n && n+sz >= sz = (CopySlice srcOff dstOff size
-              (WriteWord wOff value (ConcreteBuf simplifiedBuf)) dst)
+          | n+sz >= n
+          , n+sz >= sz
+          , n+sz <= maxBytes
+            = (CopySlice srcOff dstOff size
+                (WriteWord wOff value (ConcreteBuf simplifiedBuf)) dst)
           | otherwise = orig
             where simplifiedBuf = BS.take (unsafeInto (n+sz)) buf
     go (CopySlice a b c d f) = copySlice a b c d f