1 files changed, 14 insertions, 2 deletions

diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c
index 5aa854f9e5ae..2a5dfec8efe0 100644
--- a/kernel/ns_cgroup.c
+++ b/kernel/ns_cgroup.c
@@ -42,8 +42,8 @@ int ns_cgroup_clone(struct task_struct *task, struct pid *pid)
  *       (hence either you are in the same cgroup as task, or in an
  *        ancestor cgroup thereof)
  */
-static int ns_can_attach(struct cgroup_subsys *ss,
-                struct cgroup *new_cgroup, struct task_struct *task)
+static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup,
+                         struct task_struct *task, bool threadgroup)
 {
         if (current != task) {
                 if (!capable(CAP_SYS_ADMIN))
@@ -56,6 +56,18 @@ static int ns_can_attach(struct cgroup_subsys *ss,
         if (!cgroup_is_descendant(new_cgroup, task))
                 return -EPERM;
 
+        if (threadgroup) {
+                struct task_struct *c;
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
+                        if (!cgroup_is_descendant(new_cgroup, c)) {
+                                rcu_read_unlock();
+                                return -EPERM;
+                        }
+                }
+                rcu_read_unlock();
+        }
+
         return 0;
 }