为什么我在使用nl_recvmsgs时会收到一个Netlink ERRORMSG ?

I am trying to use nl_recvmsgs as a blocking function to receive Netlink messages from a kernel module. In my example the client sends a message to the kernel and then it calls nl_recvmsgs_report()(is equal to nl_recvmsgs). Then the kernel module sends a return message. That message is successful received by the client. as a blocking fu