static inline void sctp_copy_descendant(struct sock *sk_to,
					const struct sock *sk_from)
{
	int ancestor_size = sizeof(struct inet_sock) +
			    sizeof(struct sctp_sock) -
			    offsetof(struct sctp_sock, auto_asconf_list);

	if (sk_from->sk_family == PF_INET6)
		ancestor_size += sizeof(struct ipv6_pinfo);

	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
}
The program contains a code sequence that can run concurrently with other code, and the code sequence 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 that is operating concurrently.