C structure printing wrong value even after initializing properly - c

Question

In the program below, I am allocating memory for pointer to pointer properly and then allocating individual pointers and setting values properly, even though I am getting the garbage value to one of the structure member. I don't understand where exactly I am going wrong.
The sample output of below program is:
***CK: H2 nSupport: 0
CK: H2 nSupport: 1303643608
CK: FR2 nSupport: 0
CK: H2 nSupport: 1303643608
CK: FR2 nSupport: 0
***CK: SP2 nSupport: 0
I don't understand how I am getting the value 1303643608, though it is set properly at the beginning.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NOK 15
#define ML 100
typedef struct sample_test_for_ties_t
{
char sender[NOK];
char receiver[NOK];
char message[ML];
}sample_test_for_ties;
typedef struct CUOfS_t{
char cK[NOK];
char eK[NOK];
char nK[NOK];
char AL[ML];
int nSupport;
}CUOfS;
CUOfS **Btenders = NULL;
sample_test_for_ties test_ties[] = {
{"H2","ICY", "fmaabghijklmmcdenoopqrstuvwxyz"},
{"FR2","AIY", "fmaabghijklmmcdenoopqrstuvwxyz"},
{"SP2","LAY", "fmaabghijklmmcdenoopqrstuvwxyz"},
{"H30","ICY", "fmaabghijklmmcdenoopqrstuvwxyz"},
{"F30","AIY", "fmaabghijklmmcdenoopqrstuvwxyz"},
{"W30","LAY", "fmaabghijklmmcdenoopqrstuvwxyz"},
};
void InitBtenders(int numOfBCtenders)
{
int count =0;
if(!Btenders)
{
if(Btenders = (CUOfS **)malloc(sizeof (**Btenders) * numOfBCtenders))
{
while(count < numOfBCtenders)
{
Btenders[count] = NULL;
count++;
}
}
else
{
printf("Malloc failed\n");
}
}
}
void freeBtenders(int numOfBCtenders)
{
int count =0;
if(Btenders)
{
while(count<numOfBCtenders)
{
if(Btenders[count]) {
free(Btenders[count]);
Btenders[count] = NULL;
}
count++;
}
free(Btenders);
Btenders = NULL;
}
}
void UpdateBtendersInfo(char *aContenders)
{
static int counter =0;
if(Btenders)
{
if(Btenders[counter] == NULL) {
Btenders[counter] = (CUOfS *)malloc(sizeof (Btenders[counter]));
if(Btenders[counter])
{
strcpy(Btenders[counter]->cK,aContenders);
strcpy(Btenders[counter]->eK,"\0");
strcpy(Btenders[counter]->nK,"\0");
memset(Btenders[counter]->AL,0,sizeof(Btenders[counter]->AL));
Btenders[counter]->nSupport = 0;
counter++;
}
else
{
printf("Insufficient memory for Btender\n");
}
}
}
else
{
printf("Looks like memory not allocated for Btenders\n");
}
int count =0;
while(count <counter && Btenders[count])
{
printf("***CK: %s nSupport: %d\n",Btenders[count]->cK,Btenders[count]->nSupport);
count++;
}
printf("\n");
}
int main()
{
int numOfBCtenders = 3;
int noc =0;
InitBtenders(numOfBCtenders);
while(noc < numOfBCtenders)
{
UpdateBtendersInfo(test_ties[noc].sender);
noc++;
}
freeBtenders(numOfBCtenders);
return 0;
}
I expect
***CK: H2 nSupport: 0
But I am getting
***CK: H2 nSupport: 1303643608

Answer 1

The way you allocate memory for Btenders is incorrect.
Btenders = (CUOfS **)malloc(sizeof (**Btenders) * numOfBCtenders) // WRONG
sizeof (**Btenders) is the same as sizeof(CUOfS), but you need sizeof(CUOfS*) :
Btenders = (CUOfS **)malloc(sizeof (*Btenders) * numOfBCtenders) // FIXED
Similarly for :
Btenders[counter] = (CUOfS *)malloc(sizeof (Btenders[counter])); // WRONG
sizeof (Btenders[counter]) is the same as sizeof(CUOfS*), but you need sizeof(CUOfS) :
Btenders[counter] = (CUOfS *)malloc(sizeof (*(Btenders[counter]))); // FIXED