Good practice for freeing memory in C

main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void process_arr(int** arr, int n) {
    // processing arr
    free(*arr);
    *arr = NULL;
}

int main(int argc, char* argv[]) {
    int* arr = malloc(sizeof(int) * 10);
    process_arr(&arr, 10);
    if (arr == NULL) {
        // .... arr has been freed
    }
    
    free(arr); // if arr is NULL free() simply ignores it
    arr = NULL;
    return 0;
}