mm: memcontrol: fix possible css ref leak on oom

mem_cgroup_oom may be invoked multiple times while a process is handling
a page fault, in which case current->memcg_in_oom will be overwritten
leaking the previously taken css reference.

Link: http://lkml.kernel.org/r/1464019330-7579-1-git-send-email-vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vladimir Davydov 2016-05-23 16:22:29 -07:00 committed by Linus Torvalds
parent f43edca7ed
commit 1383399d7b

View file

@ -1604,7 +1604,7 @@ static void memcg_oom_recover(struct mem_cgroup *memcg)
static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
{
if (!current->memcg_may_oom)
if (!current->memcg_may_oom || current->memcg_in_oom)
return;
/*
* We are in the middle of the charge context here, so we