CVE-2019-16778 Heap buffer overflow in `UnsortedSegmentSum` in TensorFlow

In TensorFlow before 1.15, a heap buffer overflow in UnsortedSegmentSum can be produced when the Index template argument is int32. In this case datasize and numsegments fields are truncated from int64 to int32 and can produce negative numbers, resulting in accessing out of bounds heap memory. Thi...