static int tiocsetd(struct tty_struct *tty, int __user *p)
{
	int ldisc;
	int ret;

	if (get_user(ldisc, p))
		return -EFAULT;

	ret = tty_set_ldisc(tty, ldisc);

 	return ret;
 }

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.