If he takes the initiative to settle the loan and interest, of course the money in your passbook is still yours. You can urge the bank to go through the thawing procedures, and you can withdraw it at will when it expires, and the interest on the passbook remains unchanged. If his loan is not paid off at maturity, the bank has the right to dispose of your passbook and deduct the principal and interest of the loan in arrears.

If you don't agree, the bank won't let him take it unilaterally. If the loan has expired, you can communicate directly with the bank to understand the opinions of bank loan handling and know how to deal with it.