From: Vasily Averin <vvs@virtuozzo.com> mainline inclusion from mainline-5.6-rc3 commit 75866af62b439859d5146b7093ceb6b482852683 category: bugfix bugzilla: 30952 CVE: NA ------------------------------------------------- for_each_mem_cgroup() increases css reference counter for memory cgroup and requires to use mem_cgroup_iter_break() if the walk is cancelled. Link: http://lkml.kernel.org/r/c98414fb-7e1f-da0f-867a-9340ec4bd30b@virtuozzo.com Fixes: 0a4465d34028 ("mm, memcg: assign memcg-aware shrinkers bitmap to memcg") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 75866af62b439859d5146b7093ceb6b482852683) Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- mm/memcontrol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5d62c1f..9849166 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -419,8 +419,10 @@ int memcg_expand_shrinker_maps(int new_id) if (mem_cgroup_is_root(memcg)) continue; ret = memcg_expand_one_shrinker_map(memcg, size, old_size); - if (ret) + if (ret) { + mem_cgroup_iter_break(NULL, memcg); goto unlock; + } } unlock: if (!ret) -- 1.8.3