added a check for int overflows in ReadByteArray (#219)

* check for int overflow in ReadByteArray()

* add changelog

CHANGELOG.md

@@ -5,6 +5,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Unreleased
 
+* Added a check for int overflows in `ReadByteArray`
 * Changed valueToInt, valueToUint, valueToFload function in abiencode.go for compatible with double quoted string to number.
 * Changed `NewAssetFromString` validation to allow parsing of empty assets
 * Added `action_trace_v1` field

decoder.go

@@ -631,6 +631,10 @@ func (d *Decoder) ReadByteArray() (out []byte, err error) {
 		return nil, err
 	}
 
+	if l > math.MaxInt || d.pos > math.MaxInt-int(l) {
+		return nil, errors.New("byte array: varlen is overflowing int")
+	}
+
 	if len(d.data) < d.pos+int(l) {
 		return nil, fmt.Errorf("byte array: varlen=%d, missing %d bytes", l, d.pos+int(l)-len(d.data))
 	}