BIT-TENSORFLOW-2021-29544 CHECK-fail in `QuantizeAndDequantizeV4Grad`

TensorFlow is an end-to-end open source platform for machine learning. An attacker can trigger a denial of service via a CHECK-fail in tf.rawops.QuantizeAndDequantizeV4Grad. This is because the implementation does not validate the rank of the input tensors. In turn, this results in the tensors...