GroupPackageFinder to filter private repos

Filter out packages who the user doesnt have permission
to see (:read_package)

ee/app/finders/packages/group_packages_finder.rb

@@ -30,6 +30,8 @@ module Packages
       ::Project
         .in_namespace(groups)
         .public_or_visible_to_user(current_user, Gitlab::Access::REPORTER)
+        .with_project_feature
+        .select { |project| Ability.allowed?(current_user, :read_package, project) }
     end
 
     def package_type

ee/changelogs/unreleased/security-filter-member-only-packages-master.yml

+---
+title: Filter out packages the user does'nt have permission to see at group level
+merge_request:
+author:
+type: security

ee/spec/finders/packages/group_packages_finder_spec.rb

@@ -72,5 +72,40 @@ describe Packages::GroupPackagesFinder do
 
       it { is_expected.to match_array([package1])}
     end
+
+    context 'when project is public' do
+      set(:other_user) { create(:user) }
+      let(:finder) { described_class.new(other_user, group) }
+
+      before do
+        project.update!(visibility_level: ProjectFeature::ENABLED)
+      end
+
+      context 'when packages are public' do
+        before do
+          project.project_feature.update!(
+            builds_access_level: ProjectFeature::PRIVATE,
+            merge_requests_access_level: ProjectFeature::PRIVATE,
+            repository_access_level: ProjectFeature::ENABLED)
+        end
+
+        it 'returns group packages' do
+          expect(finder.execute).to match_array([package1, package2])
+        end
+      end
+
+      context 'packages are members only' do
+        before do
+          project.project_feature.update!(
+            builds_access_level: ProjectFeature::PRIVATE,
+            merge_requests_access_level: ProjectFeature::PRIVATE,
+            repository_access_level: ProjectFeature::PRIVATE)
+        end
+
+        it 'filters out the project if the user doesn\'t have permission' do
+          expect(finder.execute).to be_empty
+        end
+      end
+    end
   end
 end