From: Michal Hocko <mhocko@xxxxxxx> This reverts commit e4715f01be697a3730c78f8ffffb595591d6a88c mem_cgroup_put is hierarchy aware so mem_cgroup_put(memcg) already drops an additional reference from all parents so the additional mem_cgrroup_put(parent) potentially causes use-after-free. Cc: <stable@xxxxxxxxxxxxxxx> # 3.9+ Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> --- mm/memcontrol.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2e851f4..0bacc0d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6332,8 +6332,6 @@ mem_cgroup_css_online(struct cgroup *cont) * call __mem_cgroup_free, so return directly */ mem_cgroup_put(memcg); - if (parent->use_hierarchy) - mem_cgroup_put(parent); } return error; } -- 1.8.0.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>