1 files changed, 14 insertions, 1 deletions

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index fb249e2bcada..59e9ef6aab40 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -159,7 +159,7 @@ static bool is_task_frozen_enough(struct task_struct *task)
  */
 static int freezer_can_attach(struct cgroup_subsys *ss,
                               struct cgroup *new_cgroup,
-                              struct task_struct *task)
+                              struct task_struct *task, bool threadgroup)
 {
         struct freezer *freezer;
 
@@ -177,6 +177,19 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
         if (freezer->state == CGROUP_FROZEN)
                 return -EBUSY;
 
+        if (threadgroup) {
+                struct task_struct *c;
+
+                rcu_read_lock();
+                list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
+                        if (is_task_frozen_enough(c)) {
+                                rcu_read_unlock();
+                                return -EBUSY;
+                        }
+                }
+                rcu_read_unlock();
+        }
+
         return 0;
 }