Bounds checking of used_row_indices (#959) (#969)

* Bounds checking of used_row_indices (#959)

* add Common::check_int32_elements_interval_closed function.

* insert a bounds checking code in LGBM_DatasetGetSubset function of C API.

* Delete a needless function

* delete the function check_int32_elements_interval_closed

src/c_api.cpp

@@ -686,6 +686,9 @@ int LGBM_DatasetGetSubset(
   }
   auto full_dataset = reinterpret_cast<const Dataset*>(handle);
   CHECK(num_used_row_indices > 0);
+  const int32_t lower = 0;
+  const int32_t upper = full_dataset->num_data() - 1;
+  Common::CheckElementsIntervalClosed(used_row_indices, lower, upper, num_used_row_indices, "Used indices of subset");
   auto ret = std::unique_ptr<Dataset>(new Dataset(num_used_row_indices));
   ret->CopyFeatureMapperFrom(full_dataset);
   ret->CopySubset(full_dataset, used_row_indices, num_used_row_indices, true);