If a person is given some charity by someone who deals in riba, there is nothing wrong with him using that money to go for Hajj, and there is no sin on him if he accepts what is given to him, because the sin of riba is borne by the one who engages in it. As for the one who takes it in a manner that is approved of in sharee’ah, such as by being given it as a gift or a charity, there is no sin on him.
The evidence for that is the fact that the Messenger (peace and blessings of Allaah be upon him) accepted gifts from the Jews, and he ate the food of the Jews, and bought from the Jews, even though the Jews are known for dealing in riba and consuming haraam wealth.
Yes, if we assume that someone steals a sheep from a man’s flock and comes and gives it to him, then in that case it is haraam, because you know that this sheep does not belong to him. But if he was dealing in riba, then his sin is on himself, and whoever takes it from him in a manner that is approved of in sharee’ah, it is permissible for him. So we say to this woman: there is no sin on you if you go for Hajj with the money that has been given to you by one who is known to deal in riba. End quote.
Fataawa Ibn ‘Uthaymeen, 21/105.