Salim narrates from his father (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The one in ihram should not wear a shirt, a turban, trousers, a hooded cloak (burnus), garments touched by wars or saffron, or leather socks (khuffs). But whoever does not have sandals may wear leather socks, cutting them below the ankles."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9056