CVE-2020-15193: In Tensorflow before versions 2.2.1 and 2.3.1, the implementation of `dlpack.to_dlpack` can be made to use uninitialized

TensorFlow versions before 2.2.1 and 2.3.1 have a vulnerability in the `dlpack.to_dlpack` function where it can be tricked into using uninitialized memory (memory that hasn't been set to a known value), leading to further memory corruption. The problem occurs because the code assumes the input is a TensorFlow tensor, but an attacker can pass in a regular Python object instead, causing a faulty type conversion that accesses memory incorrectly.