Undefined behavior via `nullptr` reference binding in sparse matrix multiplication

Summary

TensorFlow is an open source platform for machine learning. In affected versions the code for sparse matrix multiplication is vulnerable to undefined behavior via binding a reference to `nullptr`. This occurs whenever the dimensions of `a` or `b` are 0 or less. In the case on one of these is 0, an empty output tensor should be allocated (to conserve the invariant that output tensors are always allocated when the operation is successful) but nothing should be written to it (that is, we should return early from the kernel implementation). Otherwise, attempts to write to this empty tensor would result in heap OOB access. 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, 8:50 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-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

• 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-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

References 2