diff --git a/mm/slub.c b/mm/slub.c
index 0809760cf789d1..1373ac365a46f4 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1952,7 +1952,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
 #ifdef CONFIG_MEMCG
 	new_exts |= MEMCG_DATA_OBJEXTS;
 #endif
-	old_exts = slab->obj_exts;
+	old_exts = READ_ONCE(slab->obj_exts);
 	handle_failed_objexts_alloc(old_exts, vec, objects);
 	if (new_slab) {
 		/*
@@ -1961,7 +1961,8 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
 		 * be simply assigned.
 		 */
 		slab->obj_exts = new_exts;
-	} else if (cmpxchg(&slab->obj_exts, old_exts, new_exts) != old_exts) {
+	} else if ((old_exts & ~OBJEXTS_FLAGS_MASK) ||
+		   cmpxchg(&slab->obj_exts, old_exts, new_exts) != old_exts) {
 		/*
 		 * If the slab is already in use, somebody can allocate and
 		 * assign slabobj_exts in parallel. In this case the existing