smb2_async_readv(struct cifs_readdata *rdata)
{
	int rc, flags = 0;
	char *buf;
	struct smb2_sync_hdr *shdr;
	struct cifs_io_parms io_parms;
	struct smb_rqst rqst = { .rq_iov = rdata->iov,
				 .rq_nvec = 1 };
	struct TCP_Server_Info *server;
	unsigned int total_len;

	cifs_dbg(FYI, "%s: offset=%llu bytes=%u\n",
		 __func__, rdata->offset, rdata->bytes);

	io_parms.tcon = tlink_tcon(rdata->cfile->tlink);
	io_parms.offset = rdata->offset;
	io_parms.length = rdata->bytes;
	io_parms.persistent_fid = rdata->cfile->fid.persistent_fid;
	io_parms.volatile_fid = rdata->cfile->fid.volatile_fid;
	io_parms.pid = rdata->pid;

	server = io_parms.tcon->ses->server;

	rc = smb2_new_read_req(
		(void **) &buf, &total_len, &io_parms, rdata, 0, 0);
	if (rc)
		return rc;

	if (smb3_encryption_required(io_parms.tcon))
		flags |= CIFS_TRANSFORM_REQ;

	rdata->iov[0].iov_base = buf;
	rdata->iov[0].iov_len = total_len;

	shdr = (struct smb2_sync_hdr *)buf;

	if (rdata->credits.value > 0) {
		shdr->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
						SMB2_MAX_BUFFER_SIZE));
		shdr->CreditRequest =
			cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);

		rc = adjust_credits(server, &rdata->credits, rdata->bytes);
		if (rc)
			goto async_readv_out;

		flags |= CIFS_HAS_CREDITS;
	}

	kref_get(&rdata->refcount);
	rc = cifs_call_async(io_parms.tcon->ses->server, &rqst,
			     cifs_readv_receive, smb2_readv_callback,
			     smb3_handle_read_data, rdata, flags,
			     &rdata->credits);
	if (rc) {
		kref_put(&rdata->refcount, cifs_readdata_release);
		cifs_stats_fail_inc(io_parms.tcon, SMB2_READ_HE);
		trace_smb3_read_err(0 /* xid */, io_parms.persistent_fid,
				    io_parms.tcon->tid,
				    io_parms.tcon->ses->Suid,
				    io_parms.offset, io_parms.length, rc);
	}

async_readv_out:
	cifs_small_buf_release(buf);
	return rc;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.