static void sctp_close(struct sock *sk, long timeout)
{
	struct net *net = sock_net(sk);
	struct sctp_endpoint *ep;
	struct sctp_association *asoc;
	struct list_head *pos, *temp;
	unsigned int data_was_unread;

	pr_debug("%s: sk:%p, timeout:%ld\n", __func__, sk, timeout);

	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
	sk->sk_shutdown = SHUTDOWN_MASK;
	sk->sk_state = SCTP_SS_CLOSING;

	ep = sctp_sk(sk)->ep;

	/* Clean up any skbs sitting on the receive queue.  */
	data_was_unread = sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
	data_was_unread += sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);

	/* Walk all associations on an endpoint.  */
	list_for_each_safe(pos, temp, &ep->asocs) {
		asoc = list_entry(pos, struct sctp_association, asocs);

		if (sctp_style(sk, TCP)) {
			/* A closed association can still be in the list if
			 * it belongs to a TCP-style listening socket that is
			 * not yet accepted. If so, free it. If not, send an
			 * ABORT or SHUTDOWN based on the linger options.
			 */
			if (sctp_state(asoc, CLOSED)) {
				sctp_association_free(asoc);
				continue;
			}
		}

		if (data_was_unread || !skb_queue_empty(&asoc->ulpq.lobby) ||
		    !skb_queue_empty(&asoc->ulpq.reasm) ||
		    (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime)) {
			struct sctp_chunk *chunk;

			chunk = sctp_make_abort_user(asoc, NULL, 0);
			sctp_primitive_ABORT(net, asoc, chunk);
		} else
			sctp_primitive_SHUTDOWN(net, asoc, NULL);
	}

	/* On a TCP-style socket, block for at most linger_time if set. */
	if (sctp_style(sk, TCP) && timeout)
		sctp_wait_for_close(sk, timeout);

	/* This will run the backlog queue.  */
	release_sock(sk);

	/* Supposedly, no process has access to the socket, but
	 * the net layers still may.
	 * Also, sctp_destroy_sock() needs to be called with addr_wq_lock
	 * held and that should be grabbed before socket lock.
	 */
	spin_lock_bh(&net->sctp.addr_wq_lock);
	bh_lock_sock_nested(sk);

	/* Hold the sock, since sk_common_release() will put sock_put()
	 * and we have just a little more cleanup.
	 */
	sock_hold(sk);
	sk_common_release(sk);

	bh_unlock_sock(sk);
	spin_unlock_bh(&net->sctp.addr_wq_lock);

	sock_put(sk);

	SCTP_DBG_OBJCNT_DEC(sock);
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.