Out of bounds write in Tensorflow

Impact

TensorFlow is vulnerable to a heap OOB write in Grappler:

Status SetUnknownShape(const NodeDef* node, int output_port) {
  shape_inference::ShapeHandle shape = 
      GetUnknownOutputShape(node, output_port);
  InferenceContext* ctx = GetContext(node);
  if (ctx == nullptr) {
    return errors::InvalidArgument("Missing context");
  }
  ctx->set_output(output_port, shape);
  return Status::OK();
}

The set_output function writes to an array at the specified index:

void set_output(int idx, ShapeHandle shape) { outputs_.at(idx) = shape; }

Hence, this gives a malicious user a write primitive.

Patches

We have patched the issue in GitHub commit 97282c6d0d34476b6ba033f961590b783fa184cd.

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

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