Renting back sold house, who pays maintenance?

I sold my house and I'm renting it back for 4 months. It worked best for both the buyer and myself to have this agreement. Since I'm renting, who is responsible for paying for the maintenance of the house? The dishwasher recently stopped working correctly. I'd like to call a professional to fix it. I think it's the responsibility of the new buyer to pay for the fix, but the buyer is refusing and says it's on me.