/usr/lib/ruby/vendor_ruby/rails/generators/erb/ is in ruby-railties 2:4.2.6-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/rails/generators/erb/controller/
/usr/lib/ruby/vendor_ruby/rails/generators/erb/controller/controller_generator.rb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/controller/templates/
/usr/lib/ruby/vendor_ruby/rails/generators/erb/controller/templates/view.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/mailer_generator.rb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/templates/
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/templates/layout.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/templates/layout.text.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/templates/view.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/templates/view.text.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/scaffold_generator.rb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/templates/
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/templates/_form.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/templates/edit.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/templates/index.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/templates/new.html.erb
/usr/lib/ruby/vendor_ruby/rails/generators/erb/scaffold/templates/show.html.erb