CVE-2020-15211 (C++, published 2020-09-25T19:15Z)
Description: value: In TensorFlow Lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, saved models in the flatbuffer format use a double indexing scheme: a model has a set of subgraphs, each subgraph has a set of operators and each operator has a set of input/output tensors. The flatbuffer format uses indices for the tensors, indexing into an array of tensors that is owned by the subgraph. This results in a pattern of double array indexing when trying to get the data of each tensor. However, some operators can have some tensors be optional. To handle this scenario, the flatbuffer model uses a negative `-1` value as index for these tensors. This results in special casing during validation at model loading time. Unfortunately, this means that the `-1` index is a valid tensor index for any operator, including those that don't expect optional inputs and including for output tensors. Thus, this allows writing and reading from outside the bounds of heap allocated arrays, although only at a specific offset from the start of these arrays. This results in both read and write gadgets, albeit very limited in scope. The issue is patched in several commits (46d5b0852, 00302787b7, e11f5558, cd31fd0ce, 1970c21, and fff2c83), and is released in TensorFlow versions 1.15.4, 2.0.3, 2.1.2, 2.2.1, or 2.3.1. A potential workaround would be to add a custom `Verifier` to the model loading code to ensure that only operators which accept optional inputs use the `-1` special value and only for the tensors that they expect to be optional. Since this allow-list type approach is erro-prone, we advise upgrading to the patched code.
Severity: MEDIUM (CVSS v3 base score: 4.8)
Weakness: CWE-787 \u2014 Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
Repository: https://github.com/tensorflow/tensorflow
Files changed:
tensorflow/lite/delegates/delegate_test.cc
tensorflow/lite/delegates/gpu/common/model_builder.cc
tensorflow/lite/experimental/delegates/coreml/builders/convolution_op_builder.cc
tensorflow/lite/experimental/delegates/coreml/builders/fully_connected_op_builder.cc
tensorflow/lite/experimental/delegates/coreml/builders/pad_op_builder.cc
tensorflow/lite/experimental/delegates/coreml/builders/reshape_op_builder.cc
tensorflow/lite/experimental/kernels/ctc_beam_search_decoder.cc
tensorflow/lite/experimental/kernels/unidirectional_sequence_gru.cc
tensorflow/lite/experimental/microfrontend/audio_microfrontend.cc
tensorflow/lite/interpreter_test.cc
tensorflow/lite/java/src/test/native/interpreter_test_jni.cc
tensorflow/lite/kernels/hashtable/hashtable.cc
tensorflow/lite/kernels/hashtable/hashtable_find.cc
tensorflow/lite/kernels/hashtable/hashtable_import.cc
tensorflow/lite/kernels/hashtable/hashtable_size.cc
tensorflow/lite/kernels/kernel_util.cc
tensorflow/lite/kernels/kernel_util.h
tensorflow/lite/profiling/profile_summarizer_test.cc
tensorflow/lite/tools/optimize/calibration/builtin_logging_ops/lstm.cc
Commit message: [tflite]: Insert `nullptr` checks when obtaining tensors.

As part of ongoing refactoring, `tflite::GetInput`, `tflite::GetOutput`, `tflite::GetTemporary` and `tflite::GetIntermediates` will return `nullptr` in some cases. Hence, we insert the `nullptr` checks on all usages.

We also insert `nullptr` checks on usages of `tflite::GetVariableInput` and `tflite::GetOptionalInputTensor` but only in the cases where there is no obvious check that `nullptr` is acceptable (that is, we only insert the check for the output of these two functions if the tensor is accessed as if it is always not `nullptr`).

PiperOrigin-RevId: 332517854
Change-Id: Ic27221dd1f0fbe302f311c2fe5a846ed8ff02016


Vulnerable code:
    const TfLiteTensor* input1 = GetInput(context, node, 0);
    const TfLiteTensor* input2 = GetInput(context, node, 1);
    TfLiteTensor* output = GetOutput(context, node, 0);
    const TfLiteTensor* a0 = GetInput(context, node, 0);
    const TfLiteTensor* a1 = GetInput(context, node, 1);
    TfLiteTensor* out = GetOutput(context, node, 0);
          TfLiteTensor* out = GetOutput(context, node, 0);
          const TfLiteTensor* input1 = GetInput(context, node, 0);
          TfLiteTensor* output = GetOutput(context, node, 0);
          TfLiteTensor* output = GetOutput(context, node, 0);
      TfLiteTensor* output0 = GetOutput(context, node, 0);
      const TfLiteTensor* input = GetInput(context, node, 0);
      TfLiteTensor* output1 = GetOutput(context, node, 1);
      TfLiteTensor* output0 = GetOutput(context, node, 0);
      const TfLiteTensor* input = GetInput(context, node, 0);
      TfLiteTensor* output1 = GetOutput(context, node, 1);
    auto pad_tensor = tflite::GetInput(context, tflite_node, 1);
  const TfLiteTensor* weights = GetInput(context, node, kWeightTensor);
  const TfLiteTensor* input = GetInput(context, node, kInput);
  const TfLiteTensor* weights = GetInput(context, node, kWeights);
    const TfLiteTensor* bias = GetInput(context, node, kBias);
  const TfLiteTensor* padding = GetInput(context, node, 1);
  const auto* shape = GetInput(context, node, kShapeTensor);
  const TfLiteTensor* inputs = GetInput(context, node, kInputsTensor);
  const TfLiteTensor* sequence_length =
      GetInput(context, node, kSequenceLengthTensor);
    TfLiteTensor* indices = GetOutput(context, node, i);
    TfLiteTensor* values = GetOutput(context, node, i + top_paths);
    TfLiteTensor* output_shape = GetOutput(context, node, i + 2 * top_paths);
  TfLiteTensor* log_probability_output =
      GetOutput(context, node, top_paths * 3);
    TfLiteTensor* indices = GetOutput(context, node, p);
    TfLiteTensor* values = GetOutput(context, node, p + top_paths);
    TfLiteTensor* decoded_shape = GetOutput(context, node, p + 2 * top_paths);
  const TfLiteTensor* inputs = GetInput(context, node, kInputsTensor);
  const TfLiteTensor* sequence_length =
      GetInput(context, node, kSequenceLengthTensor);
  TfLiteTensor* log_probabilities = GetOutput(context, node, 3 * top_paths);
  const TfLiteTensor* input = GetInput(context, node, kInput);
  const TfLiteTensor* input_state = GetInput(context, node, kInputState);
  const TfLiteTensor* gate_weight = GetInput(context, node, kGateWeight);
  const TfLiteTensor* gate_bias = GetInput(context, node, kGateBias);
  const TfLiteTensor* candidate_weight =
      GetInput(context, node, kCandidateWeight);
  const TfLiteTensor* candidate_bias = GetInput(context, node, kCandidateBias);
  TfLiteTensor* output = GetOutput(context, node, kOutput);
  TfLiteTensor* output_state = GetOutput(context, node, kOutputState);
  TfLiteTensor* activation = GetTemporary(context, node, kActivation);
  TfLiteTensor* concat = GetTemporary(context, node, kConcat);
  const TfLiteTensor* input = GetInput(context, node, kInput);
  const TfLiteTensor* input_state = GetInput(context, node, kInputState);
  const TfLiteTensor* gate_weight = GetInput(context, node, kGateWeight);
  const TfLiteTensor* gate_bias = GetInput(context, node, kGateBias);
  const TfLiteTensor* candidate_weight =
      GetInput(context, node, kCandidateWeight);
  const TfLiteTensor* candidate_bias = GetInput(context, node, kCandidateBias);
  TfLiteTensor* output = GetOutput(context, node, kOutput);
  TfLiteTensor* output_state = GetOutput(context, node, kOutputState);
  TfLiteTensor* activation = GetTemporary(context, node, kActivation);
  TfLiteTensor* concat = GetTemporary(context, node, kConcat);
  const TfLiteTensor* input = GetInput(context, node, kInputTensor);
  TfLiteTensor* output = GetOutput(context, node, kOutputTensor);
  const TfLiteTensor* input = GetInput(context, node, kInputTensor);
  TfLiteTensor* output = GetOutput(context, node, kOutputTensor);
    const TfLiteTensor* tensor0 = GetInput(context, node, 0);
    TfLiteTensor* tensor1 = GetOutput(context, node, 0);
    const TfLiteTensor* a0 = GetInput(context, node, 0);
    const TfLiteTensor* input = GetInput(context, node, 0);
    TfLiteTensor* output = GetOutput(context, node, 0);
    TfLiteTensor* output = GetOutput(context, node, 0);
    const TfLiteTensor* a0 = GetInput(context, node, 0);
    TfLiteTensor* a1 = GetOutput(context, node, 0);
    const TfLiteTensor* tensor0 = GetInput(context, node, 0);
    TfLiteTensor* tensor1 = GetOutput(context, node, 0);
    const TfLiteTensor* a0 = GetInput(context, node, 0);
    TfLiteTensor* a1 = GetOutput(context, node, 0);
      const TfLiteTensor* tensor0 = GetInput(context, node, 0);
      TfLiteTensor* tensor1 = GetOutput(context, node, 0);
      const TfLiteTensor* a0 = GetInput(context, node, 0);
      TfLiteTensor* a1 = GetOutput(context, node, 0);
      const TfLiteTensor* in_tensor = GetInput(context, node, 0);
      TfLiteTensor* out_tensor = GetOutput(context, node, 0);
      const TfLiteTensor* in_tensor = GetInput(context, node, 0);
      TfLiteTensor* out_tensor = GetOutput(context, node, 0);
            const TfLiteTensor* input = tflite::GetInput(context, node, 0);
            TfLiteTensor* output = tflite::GetOutput(context, node, 0);
            TfLiteTensor* output = tflite::GetOutput(context, node, 0);
  TfLiteTensor* resource_handle_tensor =
      GetOutput(context, node, kResourceHandleTensor);
  TF_LITE_ENSURE(context, resource_handle_tensor != nullptr);
  TfLiteTensor* resource_handle_tensor =
      GetOutput(context, node, kResourceHandleTensor);
  const TfLiteTensor* input_resource_id_tensor =
      GetInput(context, node, kInputResourceIdTensor);
  const TfLiteTensor* default_value_tensor =
      GetInput(context, node, kDefaultValueTensor);
  const TfLiteTensor* key_tensor = GetInput(context, node, kKeyTensor);
  TfLiteTensor* output_tensor = GetOutput(context, node, kOutputTensor);
  const TfLiteTensor* input_resource_id_tensor =
      GetInput(context, node, kInputResourceIdTensor);
  const TfLiteTensor* key_tensor = GetInput(context, node, kKeyTensor);
  const TfLiteTensor* default_value_tensor =
      GetInput(context, node, kDefaultValueTensor);
  TfLiteTensor* output_tensor = GetOutput(context, node, 0);
  const TfLiteTensor* input_resource_id_tensor =
      GetInput(context, node, kInputResourceIdTensor);
  const TfLiteTensor* key_tensor = GetInput(context, node, kKeyTensor);
  const TfLiteTensor* value_tensor = GetInput(context, node, kValueTensor);
  const TfLiteTensor* input_resource_id_tensor =
      GetInput(context, node, kInputResourceIdTensor);
  const TfLiteTensor* key_tensor = GetInput(context, node, kKeyTensor);
  const TfLiteTensor* value_tensor = GetInput(context, node, kValueTensor);
  const TfLiteTensor* input_resource_id_tensor =
      GetInput(context, node, kInputResourceIdTensor);
  TfLiteTensor* output_tensor = GetOutput(context, node, kOutputTensor);
  TF_LITE_ENSURE(context, output_tensor != nullptr);
  const TfLiteTensor* input_resource_id_tensor =
      GetInput(context, node, kInputResourceIdTensor);
  TfLiteTensor* output_tensor = GetOutput(context, node, kOutputTensor);
inline TfLiteTensor* GetMutableInput(const TfLiteContext* context,
                                     const TfLiteNode* node, int index) {
  if (index >= 0 && index < node->inputs->size) {
    const int tensor_index = node->inputs->data[index];
      if (context->tensors != nullptr) {
        return &context->tensors[tensor_index];
      } else {
        return context->GetTensor(context, tensor_index);
      }
  return nullptr;
  if (index >= 0 && index < node->outputs->size) {
    const int tensor_index = node->outputs->data[index];
    if (tensor_index != kTfLiteOptionalTensor) {
      if (context->tensors != nullptr) {
        return &context->tensors[tensor_index];
      } else {
        return context->GetTensor(context, tensor_index);
      }
    }
  return nullptr;
inline int NumDimensions(const TfLiteTensor* t) { return t->dims->size; }
inline int SizeOfDimension(const TfLiteTensor* t, int dim) {
  return t->dims->data[dim];
}

inline TfLiteTensor* GetTemporary(TfLiteContext* context,
                                  const TfLiteNode* node, int index) {
  if (index >= 0 && index < node->temporaries->size) {
    const int tensor_index = node->temporaries->data[index];
    if (tensor_index != kTfLiteOptionalTensor) {
      if (context->tensors != nullptr) {
        return &context->tensors[tensor_index];
      }
    }
  }
  return nullptr;
}
inline const TfLiteTensor* GetIntermediates(TfLiteContext* context,
                                            const TfLiteNode* node, int index) {
  if (index >= 0 && index < node->intermediates->size) {
    const int tensor_index = node->intermediates->data[index];
    if (tensor_index != kTfLiteOptionalTensor) {
      if (context->tensors != nullptr) {
        return &context->tensors[tensor_index];
      }
    }
  }
  return nullptr;
inline int NumInputs(const TfLiteNode* node) { return node->inputs->size; }
inline int NumOutputs(const TfLiteNode* node) { return node->outputs->size; }
  const TfLiteTensor* input1 = tflite::GetInput(context, node, /*index=*/0);
  const TfLiteTensor* input2 = tflite::GetInput(context, node, /*index=*/1);

  TfLiteTensor* output = GetOutput(context, node, /*index=*/0);
  const TfLiteTensor* input =
      GetInput(context, node, ops::builtin::lstm::full::kInputTensor);
  const TfLiteTensor* input_to_forget_weights = GetInput(
      context, node, ops::builtin::lstm::full::kInputToForgetWeightsTensor);
  const TfLiteTensor* input_to_cell_weights = GetInput(
      context, node, ops::builtin::lstm::full::kInputToCellWeightsTensor);
  const TfLiteTensor* input_to_output_weights = GetInput(
      context, node, ops::builtin::lstm::full::kInputToOutputWeightsTensor);
  const TfLiteTensor* recurrent_to_forget_weights = GetInput(
      context, node, ops::builtin::lstm::full::kRecurrentToForgetWeightsTensor);
  const TfLiteTensor* recurrent_to_cell_weights = GetInput(
      context, node, ops::builtin::lstm::full::kRecurrentToCellWeightsTensor);
  const TfLiteTensor* recurrent_to_output_weights = GetInput(
      context, node, ops::builtin::lstm::full::kRecurrentToOutputWeightsTensor);
  const TfLiteTensor* forget_gate_bias =
      GetInput(context, node, ops::builtin::lstm::full::kForgetGateBiasTensor);
  const TfLiteTensor* cell_gate_bias =
      GetInput(context, node, ops::builtin::lstm::full::kCellGateBiasTensor);
  const TfLiteTensor* output_gate_bias =
      GetInput(context, node, ops::builtin::lstm::full::kOutputGateBiasTensor);
  TfLiteTensor* scratch_buffer = GetTemporary(context, node, /*index=*/0);
  TfLiteTensor* output =
      GetOutput(context, node, ops::builtin::lstm::full::kOutputTensor);

Fixed code:
    const TfLiteTensor* input1;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &input1));
    const TfLiteTensor* input2;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 1, &input2));
    TfLiteTensor* output;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
    const TfLiteTensor* a0;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &a0));
    const TfLiteTensor* a1;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 1, &a1));
    TfLiteTensor* out;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &out));
          TfLiteTensor* out;
          TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &out));
          const TfLiteTensor* input1;
          TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &input1));
          TfLiteTensor* output;
          TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
          TfLiteTensor* output;
          TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
      TfLiteTensor* output0;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output0));
      const TfLiteTensor* input;
      TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &input));
      TfLiteTensor* output1;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 1, &output1));
      TfLiteTensor* output0;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output0));
      const TfLiteTensor* input;
      TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &input));
      TfLiteTensor* output1;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 1, &output1));
    if (input0 == nullptr || input1 == nullptr) {
      return absl::InvalidArgumentError("At least one input tensor is null");
    }
    const TfLiteTensor* pad_tensor = tflite::GetInput(context, tflite_node, 1);
    if (pad_tensor == nullptr) {
      return absl::InvalidArgumentError("Padding tensor was null");
    }
  const TfLiteTensor* weights;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kWeightTensor, &weights));
  const TfLiteTensor* input;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInput, &input));
  const TfLiteTensor* weights;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kWeights, &weights));
    const TfLiteTensor* bias;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kBias, &bias));
  const TfLiteTensor* padding;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 1, &padding));
  const TfLiteTensor* shape;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kShapeTensor, &shape));
  const TfLiteTensor* inputs;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kInputsTensor, &inputs));
  const TfLiteTensor* sequence_length;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kSequenceLengthTensor,
                                          &sequence_length));
    TfLiteTensor* indices;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, i, &indices));
    TfLiteTensor* values;
    TF_LITE_ENSURE_OK(context,
                      GetOutputSafe(context, node, i + top_paths, &values));
    TfLiteTensor* output_shape;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, i + 2 * top_paths,
                                             &output_shape));
  TfLiteTensor* log_probability_output;
  TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, top_paths * 3,
                                           &log_probability_output));
    TfLiteTensor* indices;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, p, &indices));
    TfLiteTensor* values;
    TF_LITE_ENSURE_OK(context,
                      GetOutputSafe(context, node, p + top_paths, &values));
    TfLiteTensor* decoded_shape;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, p + 2 * top_paths,
                                             &decoded_shape));
  const TfLiteTensor* inputs;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kInputsTensor, &inputs));
  const TfLiteTensor* sequence_length;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kSequenceLengthTensor,
                                          &sequence_length));
  TfLiteTensor* log_probabilities;
  TF_LITE_ENSURE_OK(
      context, GetOutputSafe(context, node, 3 * top_paths, &log_probabilities));
  const TfLiteTensor* input;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInput, &input));
  const TfLiteTensor* input_state;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kInputState, &input_state));
  const TfLiteTensor* gate_weight;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kGateWeight, &gate_weight));
  const TfLiteTensor* gate_bias;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kGateBias, &gate_bias));
  const TfLiteTensor* candidate_weight;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kCandidateWeight,
                                          &candidate_weight));
  const TfLiteTensor* candidate_bias;
  TF_LITE_ENSURE_OK(
      context, GetInputSafe(context, node, kCandidateBias, &candidate_bias));
  TfLiteTensor* output;
  TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, kOutput, &output));
  TfLiteTensor* output_state;
  TF_LITE_ENSURE_OK(context,
                    GetOutputSafe(context, node, kOutputState, &output_state));
  TfLiteTensor* activation;
  TF_LITE_ENSURE_OK(context,
                    GetTemporarySafe(context, node, kActivation, &activation));
  TfLiteTensor* concat;
  TF_LITE_ENSURE_OK(context, GetTemporarySafe(context, node, kConcat, &concat));
  const TfLiteTensor* input;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInput, &input));
  const TfLiteTensor* input_state;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kInputState, &input_state));
  const TfLiteTensor* gate_weight;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kGateWeight, &gate_weight));
  const TfLiteTensor* gate_bias;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kGateBias, &gate_bias));
  const TfLiteTensor* candidate_weight;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kCandidateWeight,
                                          &candidate_weight));
  const TfLiteTensor* candidate_bias;
  TF_LITE_ENSURE_OK(
      context, GetInputSafe(context, node, kCandidateBias, &candidate_bias));
  TfLiteTensor* output;
  TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, kOutput, &output));
  TfLiteTensor* output_state;
  TF_LITE_ENSURE_OK(context,
                    GetOutputSafe(context, node, kOutputState, &output_state));
  TfLiteTensor* activation;
  TF_LITE_ENSURE_OK(context,
                    GetTemporarySafe(context, node, kActivation, &activation));
  TfLiteTensor* concat;
  TF_LITE_ENSURE_OK(context, GetTemporarySafe(context, node, kConcat, &concat));
  const TfLiteTensor* input;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputTensor, &input));
  TfLiteTensor* output;
  TF_LITE_ENSURE_OK(context,
                    GetOutputSafe(context, node, kOutputTensor, &output));
  const TfLiteTensor* input;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputTensor, &input));
  TfLiteTensor* output;
  TF_LITE_ENSURE_OK(context,
                    GetOutputSafe(context, node, kOutputTensor, &output));
    const TfLiteTensor* tensor0;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &tensor0));
    TfLiteTensor* tensor1;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &tensor1));
    const TfLiteTensor* a0;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &a0));
    const TfLiteTensor* input;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &input));
    TfLiteTensor* output;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
    TfLiteTensor* output;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
    const TfLiteTensor* a0;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &a0));
    TfLiteTensor* a1;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &a1));
    const TfLiteTensor* tensor0;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &tensor0));
    TfLiteTensor* tensor1;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &tensor1));
    const TfLiteTensor* a0;
    TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &a0));
    TfLiteTensor* a1;
    TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &a1));
      const TfLiteTensor* tensor0;
      TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &tensor0));
      TfLiteTensor* tensor1;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &tensor1));
      const TfLiteTensor* a0;
      TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &a0));
      TfLiteTensor* a1;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &a1));
      const TfLiteTensor* in_tensor;
      TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &in_tensor));
      TfLiteTensor* out_tensor;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &out_tensor));
      const TfLiteTensor* in_tensor;
      TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, 0, &in_tensor));
      TfLiteTensor* out_tensor;
      TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &out_tensor));
            const TfLiteTensor* input;
            TF_LITE_ENSURE_OK(context,
                              tflite::GetInputSafe(context, node, 0, &input));
            TfLiteTensor* output;
            TF_LITE_ENSURE_OK(context,
                              tflite::GetOutputSafe(context, node, 0, &output));
            TfLiteTensor* output;
            TF_LITE_ENSURE_OK(context,
                              tflite::GetOutputSafe(context, node, 0, &output));
  TfLiteTensor* resource_handle_tensor;
  TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, kResourceHandleTensor,
                                           &resource_handle_tensor));
  TfLiteTensor* resource_handle_tensor;
  TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, kResourceHandleTensor,
                                           &resource_handle_tensor));
  const TfLiteTensor* input_resource_id_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputResourceIdTensor,
                                          &input_resource_id_tensor));
  const TfLiteTensor* default_value_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kDefaultValueTensor,
                                          &default_value_tensor));
  const TfLiteTensor* key_tensor;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kKeyTensor, &key_tensor));
  TfLiteTensor* output_tensor;
  TF_LITE_ENSURE_OK(
      context, GetOutputSafe(context, node, kOutputTensor, &output_tensor));
  const TfLiteTensor* input_resource_id_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputResourceIdTensor,
                                          &input_resource_id_tensor));
  const TfLiteTensor* key_tensor;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kKeyTensor, &key_tensor));
  const TfLiteTensor* default_value_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kDefaultValueTensor,
                                          &default_value_tensor));
  TfLiteTensor* output_tensor;
  TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output_tensor));
  const TfLiteTensor* input_resource_id_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputResourceIdTensor,
                                          &input_resource_id_tensor));
  const TfLiteTensor* key_tensor;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kKeyTensor, &key_tensor));
  const TfLiteTensor* value_tensor;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kValueTensor, &value_tensor));
  const TfLiteTensor* input_resource_id_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputResourceIdTensor,
                                          &input_resource_id_tensor));
  const TfLiteTensor* key_tensor;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kKeyTensor, &key_tensor));
  const TfLiteTensor* value_tensor;
  TF_LITE_ENSURE_OK(context,
                    GetInputSafe(context, node, kValueTensor, &value_tensor));
  const TfLiteTensor* input_resource_id_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputResourceIdTensor,
                                          &input_resource_id_tensor));
  TfLiteTensor* output_tensor;
  TF_LITE_ENSURE_OK(
      context, GetOutputSafe(context, node, kOutputTensor, &output_tensor));
  const TfLiteTensor* input_resource_id_tensor;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputResourceIdTensor,
                                          &input_resource_id_tensor));
  TfLiteTensor* output_tensor;
  TF_LITE_ENSURE_OK(
      context, GetOutputSafe(context, node, kOutputTensor, &output_tensor));
// Assumes tensor_index is a valid index (in bounds)
inline TfLiteTensor* GetTensorAtIndex(const TfLiteContext* context,
                                      int tensor_index) {
  if (context->tensors != nullptr) {
    return &context->tensors[tensor_index];
  } else {
    return context->GetTensor(context, tensor_index);
  }
}

// Validate in a single place to reduce binary size
inline TfLiteStatus ValidateTensorIndexingSafe(const TfLiteContext* context,
                                               int index, int max_size,
                                               const int* tensor_indices,
                                               int* tensor_index) {
  if (index < 0 || index >= max_size) {
    TF_LITE_KERNEL_LOG(const_cast<TfLiteContext*>(context),
                       "Invalid tensor index %d (not in [0, %d))\n", index,
                       max_size);
    return kTfLiteError;
  }
  if (tensor_indices[index] == kTfLiteOptionalTensor) {
    TF_LITE_KERNEL_LOG(const_cast<TfLiteContext*>(context),
                       "Tensor at index %d was optional but was expected\n",
                       index);
    return kTfLiteError;
  }

  *tensor_index = tensor_indices[index];
  return kTfLiteOk;
}

// Same as above but returns -1 for invalid inputs instead of status + logging
// error.
inline int ValidateTensorIndexing(const TfLiteContext* context, int index,
                                  int max_size, const int* tensor_indices) {
  if (index >= 0 && index < max_size) {
    const int tensor_index = tensor_indices[index];
      return tensor_index;
  return -1;
}

inline TfLiteTensor* GetMutableInput(const TfLiteContext* context,
                                     const TfLiteNode* node, int index) {
  const int tensor_index = ValidateTensorIndexing(
      context, index, node->inputs->size, node->inputs->data);
  if (tensor_index < 0) {
    return nullptr;
  }
  return GetTensorAtIndex(context, tensor_index);
}

inline TfLiteStatus GetMutableInputSafe(const TfLiteContext* context,
                                        const TfLiteNode* node, int index,
                                        const TfLiteTensor** tensor) {
  int tensor_index;
  TF_LITE_ENSURE_OK(
      context, ValidateTensorIndexingSafe(context, index, node->inputs->size,
                                          node->inputs->data, &tensor_index));
  *tensor = GetTensorAtIndex(context, tensor_index);
  return kTfLiteOk;
TfLiteStatus GetInputSafe(const TfLiteContext* context, const TfLiteNode* node,
                          int index, const TfLiteTensor** tensor) {
  return GetMutableInputSafe(context, node, index, tensor);
}

  const int tensor_index = ValidateTensorIndexing(
      context, index, node->outputs->size, node->outputs->data);
  if (tensor_index < 0) {
    return nullptr;
  return GetTensorAtIndex(context, tensor_index);
}

TfLiteStatus GetOutputSafe(const TfLiteContext* context, const TfLiteNode* node,
                           int index, TfLiteTensor** tensor) {
  int tensor_index;
  TF_LITE_ENSURE_OK(
      context, ValidateTensorIndexingSafe(context, index, node->outputs->size,
                                          node->outputs->data, &tensor_index));
  *tensor = GetTensorAtIndex(context, tensor_index);
  return kTfLiteOk;
#ifndef TF_LITE_STATIC_MEMORY
TfLiteTensor* GetTemporary(TfLiteContext* context, const TfLiteNode* node,
                           int index) {
  const int tensor_index = ValidateTensorIndexing(
      context, index, node->temporaries->size, node->temporaries->data);
  if (tensor_index < 0) {
    return nullptr;
  }
  return GetTensorAtIndex(context, tensor_index);
}

TfLiteStatus GetTemporarySafe(const TfLiteContext* context,
                              const TfLiteNode* node, int index,
                              TfLiteTensor** tensor) {
  int tensor_index;
  TF_LITE_ENSURE_OK(context, ValidateTensorIndexingSafe(
                                 context, index, node->temporaries->size,
                                 node->temporaries->data, &tensor_index));
  *tensor = GetTensorAtIndex(context, tensor_index);
  return kTfLiteOk;
}

const TfLiteTensor* GetIntermediates(TfLiteContext* context,
                                     const TfLiteNode* node, int index) {
  const int tensor_index = ValidateTensorIndexing(
      context, index, node->intermediates->size, node->intermediates->data);
  if (tensor_index < 0) {
    return nullptr;
  }
  return GetTensorAtIndex(context, tensor_index);
}

TfLiteStatus GetIntermediatesSafe(const TfLiteContext* context,
                                  const TfLiteNode* node, int index,
                                  TfLiteTensor** tensor) {
  int tensor_index;
  TF_LITE_ENSURE_OK(context, ValidateTensorIndexingSafe(
                                 context, index, node->intermediates->size,
                                 node->intermediates->data, &tensor_index));
  *tensor = GetTensorAtIndex(context, tensor_index);
  return kTfLiteOk;
}
#endif  // TF_LITE_STATIC_MEMORY

// Same as `GetInput` but returns boolean and uses output argument for tensor.
//
//   TfLiteTensor* my_tensor;
//   TF_LITE_ENSURE_OK(context,
//                     GetInputSafe(context, node, kMyTensorIdx, &my_tensor));
//   // can use my_tensor directly from here onwards, it is not nullptr
//
// Should be used in cases where the binary size is too large.
TfLiteStatus GetInputSafe(const TfLiteContext* context, const TfLiteNode* node,
                          int index, const TfLiteTensor** tensor);

// Same as `GetOutput` but returns boolean and uses output argument for tensor.
//
//   TfLiteTensor* my_tensor;
//   TF_LITE_ENSURE_OK(context,
//                     GetOutputSafe(context, node, kMyTensorIdx, &my_tensor));
//   // can use my_tensor directly from here onwards, it is not nullptr
//
// Should be used in cases where the binary size is too large.
TfLiteStatus GetOutputSafe(const TfLiteContext* context, const TfLiteNode* node,
                           int index, TfLiteTensor** tensor);

TfLiteTensor* GetTemporary(TfLiteContext* context, const TfLiteNode* node,
                           int index);

// Same as `GetTemporary` but returns boolean and uses output argument for
// tensor.
//
//   TfLiteTensor* my_tensor;
//   TF_LITE_ENSURE_OK(context,
//                     GetTemporarySafe(context, node, kMyTensorIdx,
//                     &my_tensor));
//   // can use my_tensor directly from here onwards, it is not nullptr
//
// Should be used in cases where the binary size is too large.
TfLiteStatus GetTemporarySafe(const TfLiteContext* context,
                              const TfLiteNode* node, int index,
                              TfLiteTensor** tensor);
const TfLiteTensor* GetIntermediates(TfLiteContext* context,
                                     const TfLiteNode* node, int index);

// Same as `GetIntermediates` but returns boolean and uses output argument for
// tensor.
//
//   TfLiteTensor* my_tensor;
//   TF_LITE_ENSURE_OK(context,
//                     GetIntermediatesSafe(context, node, kMyTensorIdx,
//                     &my_tensor));
//   // can use my_tensor directly from here onwards, it is not nullptr
//
// Should be used in cases where the binary size is too large.
TfLiteStatus GetIntermediatesSafe(const TfLiteContext* context,
                                  const TfLiteNode* node, int index,
                                  TfLiteTensor** tensor);
#endif  // TF_LITE_STATIC_MEMORY

inline int NumDimensions(const TfLiteTensor* t) { return t->dims->size; }
inline int SizeOfDimension(const TfLiteTensor* t, int dim) {
  return t->dims->data[dim];
inline int NumInputs(const TfLiteNode* node) { return node->inputs->size; }
inline int NumOutputs(const TfLiteNode* node) { return node->outputs->size; }

#ifndef TF_LITE_STATIC_MEMORY
  const TfLiteTensor* input1;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, /*index=*/0, &input1));
  const TfLiteTensor* input2;
  TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, /*index=*/1, &input2));

  TfLiteTensor* output;
  TF_LITE_ENSURE_OK(context,
                    GetOutputSafe(context, node, /*index=*/0, &output));
  const TfLiteTensor* input;
  TF_LITE_ENSURE_OK(
      context, GetInputSafe(context, node,
                            ops::builtin::lstm::full::kInputTensor, &input));
  const TfLiteTensor* input_to_forget_weights;
  TF_LITE_ENSURE_OK(
      context,
      GetInputSafe(context, node,
                   ops::builtin::lstm::full::kInputToForgetWeightsTensor,
                   &input_to_forget_weights));
  const TfLiteTensor* input_to_cell_weights;
  TF_LITE_ENSURE_OK(
      context, GetInputSafe(context, node,
                            ops::builtin::lstm::full::kInputToCellWeightsTensor,
                            &input_to_cell_weights));
  const TfLiteTensor* input_to_output_weights;
  TF_LITE_ENSURE_OK(
      context,
      GetInputSafe(context, node,
                   ops::builtin::lstm::full::kInputToOutputWeightsTensor,
                   &input_to_output_weights));
  const TfLiteTensor* recurrent_to_forget_weights;
  TF_LITE_ENSURE_OK(
      context,
      GetInputSafe(context, node,
                   ops::builtin::lstm::full::kRecurrentToForgetWeightsTensor,
                   &recurrent_to_forget_weights));
  const TfLiteTensor* recurrent_to_cell_weights;
  TF_LITE_ENSURE_OK(
      context,
      GetInputSafe(context, node,
                   ops::builtin::lstm::full::kRecurrentToCellWeightsTensor,
                   &recurrent_to_cell_weights));
  const TfLiteTensor* recurrent_to_output_weights;
  TF_LITE_ENSURE_OK(
      context,
      GetInputSafe(context, node,
                   ops::builtin::lstm::full::kRecurrentToOutputWeightsTensor,
                   &recurrent_to_output_weights));
  const TfLiteTensor* forget_gate_bias;
  TF_LITE_ENSURE_OK(
      context, GetInputSafe(context, node,
                            ops::builtin::lstm::full::kForgetGateBiasTensor,
                            &forget_gate_bias));
  const TfLiteTensor* cell_gate_bias;
  TF_LITE_ENSURE_OK(
      context,
      GetInputSafe(context, node, ops::builtin::lstm::full::kCellGateBiasTensor,
                   &cell_gate_bias));
  const TfLiteTensor* output_gate_bias;
  TF_LITE_ENSURE_OK(
      context, GetInputSafe(context, node,
                            ops::builtin::lstm::full::kOutputGateBiasTensor,
                            &output_gate_bias));
  TfLiteTensor* scratch_buffer;
  TF_LITE_ENSURE_OK(
      context, GetTemporarySafe(context, node, /*index=*/0, &scratch_buffer));
  TfLiteTensor* output;
  TF_LITE_ENSURE_OK(
      context, GetOutputSafe(context, node,
                             ops::builtin::lstm::full::kOutputTensor, &output));