1 files changed, 8 insertions, 2 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6273984f2e34..a294b7576070 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -760,7 +760,13 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
         task_unlock(task);
         if (!curr)
                 return 0;
-        if (curr->use_hierarchy)
+        /*
+         * We should check use_hierarchy of "mem" not "curr". Because checking
+         * use_hierarchy of "curr" here make this function true if hierarchy is
+         * enabled in "curr" and "curr" is a child of "mem" in *cgroup*
+         * hierarchy(even if use_hierarchy is disabled in "mem").
+         */
+        if (mem->use_hierarchy)
                 ret = css_is_ancestor(&curr->css, &mem->css);
         else
                 ret = (curr == mem);
@@ -1009,7 +1015,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
         static char memcg_name[PATH_MAX];
         int ret;
 
-        if (!memcg)
+        if (!memcg || !p)
                 return;