Don't crash on large array (#981)

Thanks to @Mike4751 for the fix

Closes #979

Author: msooseth

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Changed
 - `AbiFunction` and `AbiBytes` parser is now more strict
+- We now check length of AbiArrayDynamic and don't crash in case it's too large
 - SMT queries now run in separate processes, which allows us to better manage
   timeouts and memory usage by the SMT solver.
 - We now allow limiting the SMT solver's memory usage via `--smt-memory` (in MB).

src/EVM/ABI.hs

@@ -257,7 +257,9 @@ getAbi t = label (Text.unpack (abiTypeSolidity t)) $
 
     AbiArrayDynamicType t' -> do
       AbiUInt _ n <- label "array length" (getAbi (AbiUIntType 256))
-      AbiArrayDynamic t' <$>
+      let maxLen = fromIntegral (maxBound :: Int) :: Word256
+      if n > maxLen then fail "array length exceeds maximum Int"
+      else AbiArrayDynamic t' <$>
         label "array body" (getAbiSeq (unsafeInto n) (repeat t'))
 
     AbiTupleType ts ->