Null pointer exception when `Exit` node is not preceded by `Enter` op

Summary

TensorFlow is an open source platform for machine learning. In affected versions the process of building the control flow graph for a TensorFlow model is vulnerable to a null pointer exception when nodes that should be paired are not. This occurs because the code assumes that the first node in the pairing (e.g., an `Enter` node) always exists when encountering the second node (e.g., an `Exit` node). When this is not the case, `parent` is `nullptr` so dereferencing it causes a crash. 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.

Timeline

1. Nov 5, 2021, 8:55 PM UTCCVE published
2. Aug 4, 2024, 3:08 AM UTCRecord last updated

Affected versions

• tensorflow tensorflow

  From 2.6.0 · fixed in 2.6.1; From 2.5.0 · fixed in 2.5.2; fixed in 2.4.4

• tensorflow-gpuPyPI

  fixed in 2.4.4; From 2.5.0 · fixed in 2.5.2; From 2.6.0 · fixed in 2.6.1; From 2.7.0rc0 · fixed in 2.7.0

• tensorflowPyPI

  fixed in 2.4.4; From 2.5.0 · fixed in 2.5.2; From 2.6.0 · fixed in 2.6.1; From 2.7.0rc0 · fixed in 2.7.0

• tensorflowPyPI

  From 2.6.0 · fixed in 2.6.1

• tensorflowPyPI

  From 2.5.0 · fixed in 2.5.2

• tensorflowPyPI

  fixed in 2.4.4

• tensorflow-cpuPyPI

  From 2.6.0 · fixed in 2.6.1

• tensorflow-cpuPyPI

  From 2.5.0 · fixed in 2.5.2

• tensorflow-cpuPyPI

  fixed in 2.4.4

• tensorflow-gpuPyPI

  From 2.6.0 · fixed in 2.6.1

• tensorflow-gpuPyPI

  From 2.5.0 · fixed in 2.5.2

• tensorflow-gpuPyPI

  fixed in 2.4.4

• tensorflow-cpuPyPI

  fixed in 2.4.4; From 2.5.0 · fixed in 2.5.2; From 2.6.0 · fixed in 2.6.1; From 2.7.0rc0 · fixed in 2.7.0

References 2