Rolling Stone rocker Mick Jagger is fighting a divorce suit from model Jerry Hall by claiming their marriage was illegal, Britain’s Mirror reported Tuesday. The tabloid said 55-year-old Jagger, who has been married to Hall for eight years and has four children with her, alleged that their Hindu wedding on the Indonesian holiday island of Bali was invalid, because vital documents had never been filed. If he succeeds, Jagger could save himself a settlement of $50 million — almost a fifth of his fortune — the paper noted. Jagger and Hall have been together for 21 years and have four children: Elizabeth, 14, James, 13, Georgia May, 6, and Gabriel, 1. Hall’s divorce proceedings followed news reports about a 29-year-old Brazilian model, Luciana Giminez Mora, who claims she is five months pregnant with Jagger’s child. Jagger was divorced from his first wife, Bianca Jagger, in 1979.