Disclosures are prescribed by state law. Fair housing, which is a federal concept, pertains to issues such as using prohibited personal facts to determine whether to accept an offer. (Hazardous materials disclosures are also mandated at the federal level, but are are included in state requirements which can get pretty broad).
If you are buying in Washington state, RCW 64.06.020 says what and how you must disclose. The list of disclosures is very detailed, covering title and covenants, water, sewer, structure, systems and fixtures, environment, and mobile home related. The only one of the 86 questions about smoke is whether smoke alarms are present. Thus smell of smoke is not a legally material fact that must be disclosed, in this state. The California disclosures, even longer, are here, and there is likewise no "smells bad" disclosure.
It is unlikely that any state in the US mandates such a disclosure, since it is somewhere between a subjective evaluation and a self-evident fact. Some people are very sensitive to certain smells while others do not care. The burden is on the buyer to pursue matters of personal concern (in writing!), such as whether any dog has been present in the house in the past 5 years (some people care). You have to look carefully at the response. "Don't know" is usually a safe bet, unless you actually have factual knowledge.
From what I can determine, Massachussetts is on the opposite end of the spectrum from California. There are some requirements imposed on real estate agents, and there is the federal lead paint disclosure, but otherwise it appears that nothing is mandated by law. This form seems to be used by the real estate association, and there is a question about "history of smoke/fire damage to structure". The reasonable interpretation of that is "has the house caught fire and suffered damage", so "no" from a cigar-smoker would not be fraudulent. If the intent of the question were to reveal if someone has smoked frequently in the house, that would he the question they'd ask. You can check whether you have this form and see what it says, but "smoke damage" would not normally be interpreted as meaning "smells a bit funny".