/usr/lib/ruby/vendor_ruby/active_model/validations/ is in ruby-activemodel-3.2 3.2.16-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/active_model/validations/acceptance.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/callbacks.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/confirmation.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/exclusion.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/format.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/inclusion.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/length.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/numericality.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/presence.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/validates.rb
/usr/lib/ruby/vendor_ruby/active_model/validations/with.rb