Returning pointers back to itself - c

Question

My coding assignments came with it's header file, meaning we need to use the same data types, and not vary anything.
There is a lot of pointers, (mainly a lot of void *). Meaning things are confusing, more than difficult.
we have to do a separate function, just to increment the value referenced by a pointer. But given the nature of program, I don't want to constantly make new pointers.
The code is as follows:
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
void* intal_create(const char* );
void* intal_increment(void* );
void *intal_create(const char* str)
{
int a;
a=atoi(str);
return &a;
}
void *intal_increment(void *intal)
{
int *a= (int *)intal;//new pointer;
++*a;
//value referenced has been incremented;
*(int *)intal=*a;
return intal;
}
int main()
{
int * x;// void * return a pointer, need a pointert to int to pick it up
char *dummy;
gets(dummy);
x=(int *)intal_create(dummy);
printf("integer return is %d\n",*(int *)x);
printf("address stored is %p\n",(int *)x);
x=(int *)intal_increment(x);
printf("integer return is %d\n",*(int *)x);
printf("address stored is %p\n",(int *)x);
}
I wanted x to be the parameter called, and also for it to store the return value. The printf address is merely for my understanding.
The segmentation faults never end, and from my understanding, I'm just returning a pointer and asking a pointer to stop the return pointer

Answer 1

By incorporating all the comments. Mainly allocating memory to dummy before passing it gets() function and allocating memory in heap for the return pointer of intal_create.These two fixes solve the issue. Have a look at the following code for reference.
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
void* intal_create(const char* );
void* intal_increment(void* );
void *intal_create(const char* str)
{
int *a = (int *)malloc(sizeof(int));
*a = atoi(str);
return a;
}
void *intal_increment(void *intal)
{
//Here i am not allocating
int *a = (int *)intal;//new pointer;
(*a)++;
return intal;
}
int main()
{
int * x;// void * return a pointer, need a pointert to int to pick it up
char dummy[20] = {0};
fgets(dummy,5,stdin);
x = (int *)intal_create(dummy);
printf("integer return is %d\n",*x);
printf("address stored is %p\n",(void*)x);
x=(int *)intal_increment(x);
printf("integer return is %d\n",*x);
printf("address stored is %p\n",(void *)x);
//Make sure you deallocate the memory allocated in the intal_create function.
free(x);
}