From 2a2c7d5a12edd1304ff6b3652362b0cc74dd6a95 Mon Sep 17 00:00:00 2001
From: Mihai Maruseac <mihaimaruseac@google.com>
Date: Tue, 27 Apr 2021 17:45:43 -0700
Subject: [PATCH] Prevent another div by 0 in optimized pooling implementations
 TFLite

PiperOrigin-RevId: 370800091
Change-Id: I2119352f57fb5ca4f2051e0e2d749403304a979b
---
 tensorflow/lite/kernels/pooling.cc      |  4 ++++
 tensorflow/lite/kernels/pooling_test.cc | 13 +++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/tensorflow/lite/kernels/pooling.cc b/tensorflow/lite/kernels/pooling.cc
index 1ae3d207b135ef..474bd3825f4ff2 100644
--- a/tensorflow/lite/kernels/pooling.cc
+++ b/tensorflow/lite/kernels/pooling.cc
@@ -87,6 +87,10 @@ TfLiteStatus GenericPrepare(TfLiteContext* context, TfLiteNode* node) {
   auto padding = params->padding;
   int out_width, out_height;
 
+  // Prevent division by 0 in optimized pooling implementations
+  TF_LITE_ENSURE(context, params->stride_height > 0);
+  TF_LITE_ENSURE(context, params->stride_width > 0);
+
   data->padding = ComputePaddingHeightWidth(
       params->stride_height, params->stride_width, 1, 1, height, width,
       params->filter_height, params->filter_width, padding, &out_height,
diff --git a/tensorflow/lite/kernels/pooling_test.cc b/tensorflow/lite/kernels/pooling_test.cc
index e614fedccfd500..108195388141df 100644
--- a/tensorflow/lite/kernels/pooling_test.cc
+++ b/tensorflow/lite/kernels/pooling_test.cc
@@ -1151,5 +1151,18 @@ TEST(FloatPoolingOpTest, L2PoolPaddingValidSlide1) {
   EXPECT_THAT(m.GetOutput(), ElementsAreArray({3.5, 6.0, 6.5}));
 }
 
+#ifdef GTEST_HAS_DEATH_TEST
+TEST(FloatPoolingOpTest, MaxPoolWithZeroStride) {
+  EXPECT_DEATH(
+      FloatPoolingOpModel m(BuiltinOperator_MAX_POOL_2D,
+                            /*input=*/{TensorType_FLOAT32, {1, 2, 4, 1}},
+                            /*filter_width=*/2, /*filter_height=*/2,
+                            /*output=*/{TensorType_FLOAT32, {}},
+                            /*padding=*/Padding_VALID,
+                            /*stride_w=*/0, /*stride_h=*/0),
+      "Cannot allocate tensors");
+}
+#endif
+
 }  // namespace
 }  // namespace tflite