Fix array out-of-bounds access in WideDynamicFuncLut (#2468)
### Problem description:
In the original code, pointer arithmetic of gain_lut and the assignment of gain_lut[4 * interval + 3] could potentially lead to out-of-bounds array access.
On certain architectures (e.g., macOS ARM64), this out-of-bounds access causes the program to crash.
BUG=None, reported issue#2464
### Solution:
Increase the size of the gain_lut_storage array by 1 to provide an extra buffer and prevent overflow during the calculation within the loop.
### Risks and considerations:
Increasing the array size will slightly increase memory usage.
In extremely resource-constrained systems, alternative algorithm implementations may need to be considered.
diff --git a/python/tflite_micro/signal/utils/wide_dynamic_func_lut_wrapper.cc b/python/tflite_micro/signal/utils/wide_dynamic_func_lut_wrapper.cc
index e93e8f3..4ecf161 100644
--- a/python/tflite_micro/signal/utils/wide_dynamic_func_lut_wrapper.cc
+++ b/python/tflite_micro/signal/utils/wide_dynamic_func_lut_wrapper.cc
@@ -42,7 +42,8 @@
py::list WideDynamicFuncLut(float strength, float offset, int input_bits,
int gain_bits) {
- int16_t gain_lut_storage[kWideDynamicFunctionLUTSize];
+ // Avoid accessing outside of the buffer below gain_lut[4 * interval + 3].
+ int16_t gain_lut_storage[kWideDynamicFunctionLUTSize + 1];
int16_t* gain_lut = gain_lut_storage;
gain_lut[0] =
