SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
	   unsigned int *nbytes, struct kvec *iov, int n_vec)
{
	struct smb_rqst rqst;
	int rc = 0;
	struct smb2_write_req *req = NULL;
	struct smb2_write_rsp *rsp = NULL;
	int resp_buftype;
	struct kvec rsp_iov;
	int flags = 0;
	unsigned int total_len;

	*nbytes = 0;

	if (n_vec < 1)
		return rc;

	rc = smb2_plain_req_init(SMB2_WRITE, io_parms->tcon, (void **) &req,
			     &total_len);
	if (rc)
		return rc;

	if (io_parms->tcon->ses->server == NULL)
		return -ECONNABORTED;

	if (smb3_encryption_required(io_parms->tcon))
		flags |= CIFS_TRANSFORM_REQ;

	req->sync_hdr.ProcessId = cpu_to_le32(io_parms->pid);

	req->PersistentFileId = io_parms->persistent_fid;
	req->VolatileFileId = io_parms->volatile_fid;
	req->WriteChannelInfoOffset = 0;
	req->WriteChannelInfoLength = 0;
	req->Channel = 0;
	req->Length = cpu_to_le32(io_parms->length);
	req->Offset = cpu_to_le64(io_parms->offset);
	req->DataOffset = cpu_to_le16(
				offsetof(struct smb2_write_req, Buffer));
	req->RemainingBytes = 0;

	trace_smb3_write_enter(xid, io_parms->persistent_fid,
		io_parms->tcon->tid, io_parms->tcon->ses->Suid,
		io_parms->offset, io_parms->length);

	iov[0].iov_base = (char *)req;
	/* 1 for Buffer */
	iov[0].iov_len = total_len - 1;

	memset(&rqst, 0, sizeof(struct smb_rqst));
	rqst.rq_iov = iov;
	rqst.rq_nvec = n_vec + 1;
 
 	rc = cifs_send_recv(xid, io_parms->tcon->ses, &rqst,
 			    &resp_buftype, flags, &rsp_iov);
	cifs_small_buf_release(req);
 	rsp = (struct smb2_write_rsp *)rsp_iov.iov_base;
 
 	if (rc) {
		trace_smb3_write_err(xid, req->PersistentFileId,
				     io_parms->tcon->tid,
				     io_parms->tcon->ses->Suid,
				     io_parms->offset, io_parms->length, rc);
		cifs_stats_fail_inc(io_parms->tcon, SMB2_WRITE_HE);
		cifs_dbg(VFS, "Send error in write = %d\n", rc);
	} else {
		*nbytes = le32_to_cpu(rsp->DataLength);
		trace_smb3_write_done(xid, req->PersistentFileId,
				     io_parms->tcon->tid,
				     io_parms->tcon->ses->Suid,
 				     io_parms->offset, *nbytes);
 	}
 
 	free_rsp_buf(resp_buftype, rsp);
 	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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.