Sayyiduna Uthman bin Affan (may Allah be pleased with him) says regarding the person in ihram: He may enter a garden and smell the flowers.
Al-Tabarani recorded it in al-Mu'jam al-Saghir. Its chain contains a narrator, al-Walid bin al-Zantan; I have not found anyone who mentions him. Ibn Hibban mentioned Abu al-Walid bin al-Zantaban in his book "al-Thiqat", and he is of the same generation; apparently it is the same person, and Allah knows best. The rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الحج / 5426