memcg: avoid accessing memcg after releasing reference
This might cause a use-after-free bug.
Signed-off-by: Li Zefan <[email protected]>
Cc: Glauber Costa <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: KAMEZAWA Hiroyuki <[email protected]>
Cc: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 360464f..c92bcfc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3215,12 +3215,12 @@
root = s->memcg_params->root_cache;
root->memcg_params->memcg_caches[id] = NULL;
- mem_cgroup_put(memcg);
mutex_lock(&memcg->slab_caches_mutex);
list_del(&s->memcg_params->list);
mutex_unlock(&memcg->slab_caches_mutex);
+ mem_cgroup_put(memcg);
out:
kfree(s->memcg_params);
}
