Ibn Masud performed the two prostrations of forgetfulness after the salutation and mentioned that the Prophet ﷺ had done the same.
حدثنا أبو بكر بن خلاد حدثنا سفيان بن عيينة عن منصور عن إبراهيم
أن ابن مسعود سجد سجدتي السهو بعد السلام وذكر أن النبي ﷺ فعل ذلك
[Sahih] Ahmad narrated it, 1/376, from Sufyan, with this same wording, and the wording of Humaydi in his Musnad is, Sufyan narrated to us from Mansur with this same wording. It has corroborating narrations in Muslim, no. 572, and Bukhari, no. 401, and others.