`CHECK`-failures during Grappler's `IsSimplifiableReshape` in Tensorflow

Impact

The Grappler optimizer in TensorFlow can be used to cause a denial of service by altering a SavedModel such that IsSimplifiableReshape would trigger CHECK failures.

Patches

We have patched the issue in GitHub commits ebc1a2ffe5a7573d905e99bd0ee3568ee07c12c1, 1fb27733f943295d874417630edd3b38b34ce082, and 240655511cd3e701155f944a972db71b6c0b1bb6.

The fix will be included in TensorFlow 2.8.0. We will also cherrypick this commit on TensorFlow 2.7.1, TensorFlow 2.6.3, and TensorFlow 2.5.3, as these are also affected and still in supported range.

For more information

Please consult our security guide for more information regarding the security model and how to contact us with issues and questions.