static void tty_flush_works(struct tty_struct *tty)
{
	flush_work(&tty->SAK_work);
	flush_work(&tty->hangup_work);
	if (tty->link) {
		flush_work(&tty->link->SAK_work);
		flush_work(&tty->link->hangup_work);
	}
}

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.