Subject ( receiver of the action )  +  Verb ( action )  +  Object ( doer of the action )    How is    the subject passive?

Hello,

Here the subject in the sentence is the receiver of the action. The impact of the verb falls on the subject. The subject isn't the person responsible for the action to take place. Thus, the subject differs from the doer of the action, also known as the object of the sentence.

Hope your doubt got cleared!