static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len,
				    char __user *optval, int __user *optlen)
{
	struct sctp_endpoint *ep = sctp_sk(sk)->ep;
	struct sctp_authchunks __user *p = (void __user *)optval;
	struct sctp_authchunks val;
	struct sctp_association *asoc;
	struct sctp_chunks_param *ch;
	u32    num_chunks = 0;
	char __user *to;

	if (!ep->auth_enable)
		return -EACCES;

	if (len < sizeof(struct sctp_authchunks))
		return -EINVAL;

	if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks)))
		return -EFAULT;

	to = p->gauth_chunks;
	asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
	if (!asoc)
		return -EINVAL;

	ch = asoc->peer.peer_chunks;
	if (!ch)
		goto num;

	/* See if the user provided enough room for all the data */
	num_chunks = ntohs(ch->param_hdr.length) - sizeof(struct sctp_paramhdr);
	if (len < num_chunks)
		return -EINVAL;

	if (copy_to_user(to, ch->chunks, num_chunks))
		return -EFAULT;
num:
	len = sizeof(struct sctp_authchunks) + num_chunks;
	if (put_user(len, optlen))
		return -EFAULT;
	if (put_user(num_chunks, &p->gauth_number_of_chunks))
		return -EFAULT;
	return 0;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.