Segfault due to negative splits in `SplitV`

Impact

The implementation of SplitV can trigger a segfault is an attacker supplies negative arguments:

import tensorflow as tf

tf.raw_ops.SplitV(
  value=tf.constant([]),
  size_splits=[-1, -2]
  ,axis=0,
  num_split=2)

This occurs whenever size_splits contains more than one value and at least one value is negative.

Patches

We have patched the issue in GitHub commit 25d622ffc432acc736b14ca3904177579e733cc6.

The fix will be included in TensorFlow 2.7.0. We will also cherrypick this commit on TensorFlow 2.6.1, TensorFlow 2.5.2, and TensorFlow 2.4.4, 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.

Attribution

This vulnerability has been reported by members of the Aivul Team from Qihoo 360.