[PATCH v4] nvmet-tcp: fix a segmentation fault during io parsing error

[Hou Pu]

On Tue, 30 Mar 2021 20:24:07 +0300, Elad wrote:
> @@ -960,7 +981,7 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
>  			le32_to_cpu(req->cmd->common.dptr.sgl.length));
> 
>  		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
> -		return -EAGAIN;
> +		return 0;
>  	}
> 
>  	ret = nvmet_tcp_map_data(queue->cmd);

Hi Elad
By returning 0, the response is queued twice before it is get off from the
list. Even still returning -EAGAIN, the cmd still could be queued twice
potentially.

I think we'd better not queue the failed cmd in first place.
Please see my following fix later.

Thanks,
Hou