CVE-2021-37679 Heap OOB in nested `tf.map_fn` with `RaggedTensor`s in TensorFlow

TensorFlow is an end-to-end open source platform for machine learning. In affected versions it is possible to nest a tf.mapfn within another tf.mapfn call. However, if the input tensor is a RaggedTensor and there is no function signature provided, code assumes the output is a fully specified tens...