Memory Leak in C When Using `malloc` with Custom Array Structs
I've hit a wall trying to I'm refactoring my project and I am working with a memory leak scenario in my C program that involves dynamically allocating memory for a custom struct representing a 2D array. The struct definition looks like this: ```c typedef struct { int rows; int cols; int **data; } Array2D; ``` I have a function that initializes this struct and allocates memory for the 2D array as follows: ```c Array2D* createArray(int rows, int cols) { Array2D* arr = (Array2D*)malloc(sizeof(Array2D)); if (arr == NULL) return NULL; arr->rows = rows; arr->cols = cols; arr->data = (int**)malloc(rows * sizeof(int*)); for (int i = 0; i < rows; i++) { arr->data[i] = (int*)malloc(cols * sizeof(int)); } return arr; } ``` I thought I had handled the memory allocation properly, but when I run my program with Valgrind, it reports a memory leak. The leak seems to be in the `createArray` function when I free the memory. Here is my cleanup function: ```c void freeArray(Array2D* arr) { if (arr != NULL) { for (int i = 0; i < arr->rows; i++) { free(arr->data[i]); } free(arr->data); free(arr); } } ``` The memory leak occurs even when I call `freeArray` for the allocated `Array2D` struct. I have been careful to call `free()` for each allocated pointer and then for the struct itself, yet Valgrind still shows memory still in use after the program exits. I’ve tried running the program with a simplified version where I allocate and free just a single row and column, and it worked without leaks. However, it seems something goes wrong when I use multiple rows. Is there anything I might be overlooking or a common pitfall with dynamic memory allocation in C that could cause this scenario? My development environment is GCC 11.2 and I'm running on Ubuntu 20.04. Am I approaching this the right way? Any ideas what could be causing this? I recently upgraded to C 3.11. What's the correct way to implement this?