Переполнение стека при освобождении памяти

bool unload(void)
{
   node* current = LAST;
    
    int counter = 0;
    for (int i = 0; i < 27; i++)
     {
       if (current->next[i] != NULL)
        {          
          LAST = current->next[i];
          return unload();
        }
         else 
          {counter++;}      
     }
          
     if (counter == 27)
     {
       if (current->next[27] == NULL)
        {
         for (int i = 0; i < 28; i++)
          {
           if (FIRST->next[i] != NULL)
            {
             return false;               
            }
            else if (i == 27)
            {
             free(FIRST);
             return true;               
            }
          }
        }
      LAST = current->next[27];
      free(current);
       for (int i = 0; i < 27; i++)
       {
        if ((LAST->next[i] != NULL) && (counter2 == 0))
         {
          LAST->next[i] = NULL;
          counter2++;
         }         
 
       }
       counter2 = 0;
       return unload();  
     }
     
   
return true;      
}

==9497== Stack overflow in thread 1: can't grow stack to 0xbe197ffc
==9497== 
==9497== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==9497==  Access not within mapped region at address 0xBE197FFC
==9497==    at 0x8048B2C: unload (load.c:170)
==9497==  If you believe this happened as a result of a stack
==9497==  overflow in your program's main thread (unlikely but
==9497==  possible), you can try to increase the size of the
==9497==  main thread stack using the --main-stacksize= flag.
==9497==  The main thread stack size used in this run was 8388608.
==9497== Stack overflow in thread 1: can't grow stack to 0xbe197ff8
==9497== 
==9497== Process terminating with default action of signal 11 (SIGSEGV)
==9497==  Access not within mapped region at address 0xBE197FF8
==9497==    at 0x4024510: _vgnU_freeres (in /usr/lib/valgrind/vgpreload_core-x86-linux.so)
==9497==  If you believe this happened as a result of a stack
==9497==  overflow in your program's main thread (unlikely but
==9497==  possible), you can try to increase the size of the
==9497==  main thread stack using the --main-stacksize= flag.
==9497==  The main thread stack size used in this run was 8388608.
==9497== 
==9497== HEAP SUMMARY:
==9497==     in use at exit: 32,352,056 bytes in 278,895 blocks
==9497==   total heap usage: 366,187 allocs, 87,292 frees, 42,477,928 bytes allocated
==9497== 
==9497== LEAK SUMMARY:
==9497==    definitely lost: 0 bytes in 0 blocks
==9497==    indirectly lost: 0 bytes in 0 blocks
==9497==      possibly lost: 0 bytes in 0 blocks
==9497==    still reachable: 32,352,056 bytes in 278,895 blocks
==9497==         suppressed: 0 bytes in 0 blocks
==9497== Reachable blocks (those to which a pointer was found) are not shown.
==9497== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==9497== 
==9497== For counts of detected and suppressed errors, rerun with: -v
==9497== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)