diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c index 432fcbbd14d4..326d9ac65145 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -694,7 +694,6 @@ static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, static s64 hvs_stream_has_data(struct vsock_sock *vsk) { struct hvsock *hvs = vsk->trans; - bool need_refill; s64 ret; if (hvs->recv_data_len > 0) @@ -702,9 +701,31 @@ static s64 hvs_stream_has_data(struct vsock_sock *vsk) switch (hvs_channel_readable_payload(hvs->chan)) { case 1: - need_refill = !hvs->recv_desc; - if (!need_refill) - return -EIO; + if (hvs->recv_desc) { + /* Here hvs->recv_data_len is 0, so hvs->recv_desc must + * be NULL unless it points to the 0-byte-payload FIN + * packet or a malformed/short packet: see + * hvs_update_recv_data(). + * + * If hvs->recv_desc points to the FIN packet, here all + * the payload has been dequeued and the peer_shutdown + * flag is set, but hvs_channel_readable_payload() still + * returns 1, because the VMBus ringbuffer's read_index + * is not updated for the FIN packet: + * hvs_stream_dequeue() -> hv_pkt_iter_next() updates + * the cached priv_read_index but has no opportunity to + * update the read_index in hv_pkt_iter_close() as + * hvs_stream_has_data() returns 0 for the FIN packet, + * so it won't get dequeued. + * + * In case hvs->recv_desc points to a malformed/short + * packet, return -EIO. + */ + if (!(vsk->peer_shutdown & SEND_SHUTDOWN)) + return -EIO; + + return 0; + } hvs->recv_desc = hv_pkt_iter_first(hvs->chan); if (!hvs->recv_desc)