It was narrated from Ibn ‘Umar that the Prophet (ﷺ) used to put oil on his head when he was in the state of Ihram, but not oil that was perfumed.

حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، عَنْ فَرْقَدٍ السَّبَخِيِّ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عُمَرَ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ كَانَ يَدَّهِنُ رَأْسَهُ بِالزَّيْتِ وَهُوَ مُحْرِمٌ غَيْرَ الْمُقَتَّتِ ‏.‏