If you are asking about the ruling on
carrying cigarettes to the Masjid, there is no doubt that cigarettes are very bad and harmful. It is unlawful to smoke because it consumes the person's health and money and harms the society. Also, there is no good in smoking. Since smoking is bad and harmful, we have to keep cigarettes away from the places of worship. In fact, carrying cigarettes to the Masjid contradicts the necessity of revering the places of worship; and so it is not permissible. If you are asking about the validity of Salah
of a person from whom a packet of cigarettes fell during Salah, (Part No. 22; Page No. 184) the Salah is valid.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.