diff --git a/ipc/shm.c b/ipc/shm.c
index 0a5053f5726f6bf6ab0f2f26b6c16ab73a82829c..14282b7f9800ea5f2625904e89a5ab8cfc8f6d64 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -417,8 +417,11 @@ static int shm_try_destroy_orphaned(int id, void *p, void *data)
 void shm_destroy_orphaned(struct ipc_namespace *ns)
 {
 	down_write(&shm_ids(ns).rwsem);
-	if (shm_ids(ns).in_use)
+	if (shm_ids(ns).in_use) {
+		rcu_read_lock();
 		idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
+		rcu_read_unlock();
+	}
 	up_write(&shm_ids(ns).rwsem);
 }