diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3504125871d2..ce131d25622a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9611,6 +9611,8 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
 	if (ret)
 		return -EFAULT;
 
+	attr->size = size;
+
 	if (attr->__reserved_1)
 		return -EINVAL;