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>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b3f16ab..cf428d7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1604,7 +1604,7 @@
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