 void buffer_slow_realign(struct buffer *buf)
 {
       int block1 = buf->o;
       int block2 = 0;

       /* process output data in two steps to cover wrapping */
       if (block1 > buf->p - buf->data) {
               block2 = buf->p - buf->data;
               block1 -= block2;
       }
       memcpy(swap_buffer + buf->size - buf->o, bo_ptr(buf), block1);
       memcpy(swap_buffer + buf->size - block2, buf->data, block2);

       /* process input data in two steps to cover wrapping */
       block1 = buf->i;
       block2 = 0;

       if (block1 > buf->data + buf->size - buf->p) {
               block1 = buf->data + buf->size - buf->p;
               block2 = buf->i - block1;
        }
       memcpy(swap_buffer, bi_ptr(buf), block1);
       memcpy(swap_buffer + block1, buf->data, block2);

       /* reinject changes into the buffer */
       memcpy(buf->data, swap_buffer, buf->i);
       memcpy(buf->data + buf->size - buf->o, swap_buffer + buf->size - buf->o, buf->o);
 
        buf->p = buf->data;
 }

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.