Integer overflow in TFLite array creation

Impact

An attacker can craft a TFLite model that would cause an integer overflow in TfLiteIntArrayCreate:

TfLiteIntArray* TfLiteIntArrayCreate(int size) {
  int alloc_size = TfLiteIntArrayGetSizeInBytes(size);
  // ...
  TfLiteIntArray* ret = (TfLiteIntArray*)malloc(alloc_size);
  // ...
} 

The TfLiteIntArrayGetSizeInBytes returns an int instead of a size_t:

int TfLiteIntArrayGetSizeInBytes(int size) {
  static TfLiteIntArray dummy;

  int computed_size = sizeof(dummy) + sizeof(dummy.data[0]) * size;
#if defined(_MSC_VER)
  // Context for why this is needed is in http://b/189926408#comment21
  computed_size -= sizeof(dummy.data[0]);
#endif
  return computed_size;
}

An attacker can control model inputs such that computed_size overflows the size of int datatype.

Patches

We have patched the issue in GitHub commit a1e1511dde36b3f8aa27a6ec630838e7ea40e091.

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.

Attribution

This vulnerability has been reported by Wang Xuan of Qihoo 360 AIVul Team.