Merge branch '19102-fix' into 'master'

Fix an information disclosure when requesting access to a group containing private projects

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19102.

The commit speaks for itself:

    Fix an information disclosure when requesting access to a group containing private projects
    
    The issue was with the `User#groups` and `User#projects` associations
    which goes through the `User#group_members` and `User#project_members`.
    
    Initially I chose to use a secure approach by storing the requester's
    user ID in `Member#created_by_id` instead of `Member#user_id` because I
    was aware that there was a security risk since I didn't know the
    codebase well enough.
    
    Then during the review, we decided to change that and directly store the
    requester's user ID into `Member#user_id` (for the sake of simplifying
    the code I believe), meaning that every `group_members` / `project_members`
    association would include the requesters by default...
    
    My bad for not checking that all the `group_members` / `project_members`
    associations and the ones that go through them (e.g. `Group#users` and
    `Project#users`) were made safe with the `where(requested_at: nil)` /
    `where(members: { requested_at: nil })` scopes.
    
    Now they are all secure.

See merge request !1973

1 files changed, 3 insertions, 2 deletions

diff --git a/app/views/admin/users/groups.html.haml b/app/views/admin/users/groups.html.haml
index b0a709a568a..8f6d13b881a 100644
--- a/app/views/admin/users/groups.html.haml
+++ b/app/views/admin/users/groups.html.haml
@@ -1,11 +1,12 @@
 - page_title "Groups", @user.name, "Users"
 = render 'admin/users/head'
 
-- if @user.group_members.present?
+- group_members = @user.group_members.includes(:source)
+- if group_members.any?
   .panel.panel-default
     .panel-heading Groups:
     %ul.well-list
-      - @user.group_members.each do |group_member|
+      - group_members.each do |group_member|
         - group = group_member.group
         %li.group_member
           %span{class: ("list-item-name" unless group_member.owner?)}