C语言传递空指针

int* allocateArray(int *arr, int size, int value) {
    if(arr != NULL) {
        for(int i=0; i<size; i++) {
            arr[i] = value;
        }
    }
    return arr;
}

int* vector = (int*)malloc(5 * sizeof(int));
allocateArray(vector,5,45);