diff --git a/fs/namespace.c b/fs/namespace.c
index 4494064205a6..1390e9e521d6 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -5138,6 +5138,8 @@ SYSCALL_DEFINE4(listmount, const struct mnt_id_req __user *, req,
 
 	scoped_guard(rwsem_read, &namespace_sem)
 		ret = do_listmount(kreq.mnt_id, kreq.param, kmnt_ids, nr_mnt_ids);
+	if (ret <= 0)
+		return ret;
 
 	if (copy_to_user(mnt_ids, kmnt_ids, ret * sizeof(*mnt_ids)))
 		return -EFAULT;