Muwatta Malik:Fasting:Hadith 668
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، أَنَّ أَبَا هُرَيْرَةَ، وَسَعْدَ بْنَ أَبِي وَقَّاصٍ، كَانَا يُرَخِّصَانِ فِي الْقُبْلَةِ لِلصَّائِمِ ‏.‏

Yahya related to me from Malik from Zayd ibn Aslam that Abu Hurayra and Sad ibn Abi Waqqas used to say that someone who was fasting was allowed to kiss.