It is narrated from Ibn Umar (may Allah be pleased with them both) that a man asked the Prophet (ﷺ): "What clothes should a person in Ihram wear?" The Messenger of Allah (ﷺ) replied: "A person in Ihram should not wear a shirt, trousers, turbans, caps, or socks. And if someone does not have shoes, he should cut the socks below the ankles and wear them."
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 838
Hadith Takhrijاخرجه البخاري، الحج، باب ما لا يلبس المحرم من الثياب (1532) ومسلم ، الحج، باب ما يباح للمحرم بحج او عمرة لبسة..... الخ (1177)۔