I thought it was recently established that you can't sue downstream providers, or at least that doing so is useless. Maybe that's just my interpretation of the LG v. Quanta suit that got slapped down because LG had exhausted its patent rights with Intel and couldn't chase the downstream provider Quanta. All these distributors would be immune if the suit fails or if it succeeds and Red Hat licenses the patent.
Redhat is no longer a down stream provider, they own JBoss