Queuing function in C

I've created the following queue:

typedef struct
No {
    int pos;
    char cpf[12];
    char nome[40];
    struct No *prox;
} No;
typedef struct No * p_no;

typedef struct{
    p_no ini, fim;
} Fila;
typedef Fila * p_fila;

And I have the following function to queue:

void enfileira(p_fila f, int pos, char cpf[], char nome[]) {
    p_no novo;
    novo = malloc(sizeof(No));
    novo->pos = pos;
    strcpy(novo->cpf, cpf);
    strcpy(novo->nome, nome);

    novo->prox = NULL;
    if(f->ini == NULL)
            f->ini = novo;
    else
            f->fim->prox = novo;
    f->fim = novo;
}

However, when I run Valgrind to check for memory errors, it says that some blocks are being lost:

==16485== HEAP SUMMARY:
==16485==     in use at exit: 600 bytes in 10 blocks
==16485==   total heap usage: 19 allocs, 9 frees, 6,036 bytes allocated
==16485== 
==16485== 300 (60 direct, 240 indirect) bytes in 1 blocks are definitely lost in loss record 3 of 4
==16485==    at 0x482E27C: malloc (vg_replace_malloc.c:299)
==16485==    by 0x108709: enfileira (in /home/student/Downloads/lab06)
==16485==    by 0x108E83: main (in /home/student/Downloads/lab06)
==16485== 
==16485== 300 (60 direct, 240 indirect) bytes in 1 blocks are definitely lost in loss record 4 of 4
==16485==    at 0x482E27C: malloc (vg_replace_malloc.c:299)
==16485==    by 0x108709: enfileira (in /home/student/Downloads/lab06)
==16485==    by 0x109245: main (in /home/student/Downloads/lab06)

I understand that it's because I'm not dealing with some part of the queue (I imagine). But I've already created the queue function and called it in main() , but the error persists:

void libera_fila (p_fila f)
{
      p_no t;
      while(f->ini != NULL){
          t = f->ini;
          f->ini = f->ini->prox;
          free(t);
      }
      free(f);


}