memcg: fix possible use-after-free in memcg_kmem_get_cache()

[mirror_ubuntu-hirsute-kernel.git] / include / linux / memcontrol.h

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b74942a9e22f3935a471960215851620018b0fbf..7c95af8d552cffd0dd260b66ca162efd8ef608cf 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -400,8 +400,8 @@ int memcg_cache_id(struct mem_cgroup *memcg);
 
 void memcg_update_array_size(int num_groups);
 
-struct kmem_cache *
-__memcg_kmem_get_cache(struct kmem_cache *cachep);
+struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep);
+void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 
 int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order);
 void __memcg_uncharge_slab(struct kmem_cache *cachep, int order);
@@ -494,6 +494,12 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 
        return __memcg_kmem_get_cache(cachep);
 }
+
+static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
+{
+       if (memcg_kmem_enabled())
+               __memcg_kmem_put_cache(cachep);
+}
 #else
 #define for_each_memcg_cache_index(_idx)       \
        for (; NULL; )
@@ -528,6 +534,10 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 {
        return cachep;
 }
+
+static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
+{
+}
 #endif /* CONFIG_MEMCG_KMEM */
 #endif /* _LINUX_MEMCONTROL_H */