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)