1 files changed, 23 insertions, 10 deletions
diff --git a/app/services/merge_requests/create_service.rb b/app/services/merge_requests/create_service.rb
index 49cf534dc0d..a18b1c90765 100644
--- a/app/services/merge_requests/create_service.rb
+++ b/app/services/merge_requests/create_service.rb
@@ -1,22 +1,15 @@
 module MergeRequests
   class CreateService < MergeRequests::BaseService
     def execute
-      # @project is used to determine whether the user can set the merge request's
-      # assignee, milestone and labels. Whether they can depends on their
-      # permissions on the target project.
-      source_project = @project
-      @project = Project.find(params[:target_project_id]) if params[:target_project_id]
+      set_projects!
 
       merge_request = MergeRequest.new
       merge_request.target_project = @project
-      merge_request.source_project = source_project
+      merge_request.source_project = @source_project
       merge_request.source_branch = params[:source_branch]
       merge_request.merge_params['force_remove_source_branch'] = params.delete(:force_remove_source_branch)
 
-      # n+1: https://gitlab.com/gitlab-org/gitlab-ce/issues/37439
-      Gitlab::GitalyClient.allow_n_plus_1_calls do
-        create(merge_request)
-      end
+      create(merge_request)
     end
 
     def before_create(merge_request)
@@ -58,5 +51,25 @@ module MergeRequests
 
       pipelines.order(id: :desc).first
     end
+
+    def set_projects!
+      # @project is used to determine whether the user can set the merge request's
+      # assignee, milestone and labels. Whether they can depends on their
+      # permissions on the target project.
+      @source_project = @project
+      @project = Project.find(params[:target_project_id]) if params[:target_project_id]
+
+      # make sure that source/target project ids are not in
+      # params so it can't be overridden later when updating attributes
+      # from params when applying quick actions
+      params.delete(:source_project_id)
+      params.delete(:target_project_id)
+
+      unless can?(current_user, :read_project, @source_project) &&
+          can?(current_user, :read_project, @project)
+
+        raise Gitlab::Access::AccessDeniedError
+      end
+    end
   end
 end