mm/memcontrol.c: add missed css_put()

commit 3a98990ae2150277ed34d3b248c60e68bf2244b2 upstream.

We should put the css reference when memory allocation failed.

Link: http://lkml.kernel.org/r/20200614122653.98829-1-songmuchun@bytedance.com
Fixes: f0a3a24b532d ("mm: memcg/slab: rework non-root kmem_cache lifecycle management")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0d6f3ea..a3f4c35 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2895,8 +2895,10 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
                return;
 
        cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN);
-       if (!cw)
+       if (!cw) {
+               css_put(&memcg->css);
                return;
+       }
 
        cw->memcg = memcg;
        cw->cachep = cachep;