Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "The seller and the buyer each have the option to cancel the deal until they part, except when the sale between them is one with an option."
(b) In the narration of al-Shafi'i it says: "He has the option over his companion."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10430