c Function that generates an array of pointers

Question

Hello just looking to implement a function that initializes an array of char pointers in the string_split function bellow. wondering how to properly do this currently getting a segmentation fault. The segmentation fault occurs when i try to print the tokens in the main function. I may be approaching this the wrong way if so please point me in the right direction.

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

uint32_t string_split(char **tokens, char *buffer,uint32_t len, char del);
uint32_t character_count(char * str, char c);


int main (int argc, char *argv[]) 
{
    uint32_t i,len;
    char * buffer = 0;
    long length;
    FILE * f;
    char **tokens = NULL;
        
        
    if (argc < 2)
    {
        printf("usage: %s <config_file>\n\r" , argv[0]);
        return 0;
    }


    f = fopen(argv[1], "rb");
    if (f)
    {
        fseek(f, 0, SEEK_END);
        length = ftell(f);
        fseek(f, 0, SEEK_SET);
        buffer = malloc(length + 1);
        if (buffer)
        {
            fread(buffer, 1, length, f);
            buffer[length] = '\0';
        }
        fclose(f);
    }

    if (buffer)
    {
        //printf("%s", buffer);
        len = string_split(tokens, buffer, strlen(buffer), '\n');
        printf("len:%d\n\r", len);

        for(i = 0; i < len; i++)
        {
            printf("%s\n\r", tokens[i]);

        }
        // start to process your data / extract strings here...
    }
    return 0;
}



uint32_t string_split(char **tokens, char *buffer,uint32_t len, char del)
{
    uint32_t i, size, cnt;
    char *token = NULL;

    cnt = 0;
    size = character_count(buffer,del);
    //printf("size:%d\n\r", size);
    tokens = malloc(size* sizeof(char *));

    for(i=0; i < size; i++)
    {
        tokens[i] = NULL;
    }
    
    token = strtok(buffer, &del);
    tokens[cnt] = token;
    cnt++;

   while( token != NULL ) {
      //printf( " %s\n", token ); //printing each token
      token = strtok(NULL, &del);
      if (token != NULL)
      {
          tokens[cnt] = token;
          cnt++;
      }
   }
    return cnt;

}


uint32_t character_count(char * str, char c)
{
    uint32_t i,cnt;

    cnt = 0;
    for(i=0; i < strlen(str); i++)
    {
        if (str[i] == c)
            cnt++;
    }

    return cnt;

}