static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
					   char __user *optval,
					   int __user *optlen)
{
	struct sctp_stream_out *streamout;
	struct sctp_association *asoc;
	struct sctp_prstatus params;
	int retval = -EINVAL;
	int policy;

	if (len < sizeof(params))
		goto out;

	len = sizeof(params);
	if (copy_from_user(&params, optval, len)) {
		retval = -EFAULT;
		goto out;
	}

	policy = params.sprstat_policy;
	if (policy & ~SCTP_PR_SCTP_MASK)
		goto out;

	asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
	if (!asoc || params.sprstat_sid >= asoc->stream.outcnt)
		goto out;

	streamout = &asoc->stream.out[params.sprstat_sid];
	if (policy == SCTP_PR_SCTP_NONE) {
		params.sprstat_abandoned_unsent = 0;
		params.sprstat_abandoned_sent = 0;
		for (policy = 0; policy <= SCTP_PR_INDEX(MAX); policy++) {
			params.sprstat_abandoned_unsent +=
				streamout->abandoned_unsent[policy];
			params.sprstat_abandoned_sent +=
				streamout->abandoned_sent[policy];
		}
	} else {
		params.sprstat_abandoned_unsent =
			streamout->abandoned_unsent[__SCTP_PR_INDEX(policy)];
		params.sprstat_abandoned_sent =
			streamout->abandoned_sent[__SCTP_PR_INDEX(policy)];
	}

	if (put_user(len, optlen) || copy_to_user(optval, &params, len)) {
		retval = -EFAULT;
		goto out;
	}

	retval = 0;

out:
	return retval;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.