ALSA: seq: Fix races at MIDI encoding in snd_virmidi_output_trigger()

[mirror_ubuntu-bionic-kernel.git] / sound / core / seq / seq_virmidi.c

diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c
index f48a4cd24ffce2d50639e177822bb96b31a93d02..289ae6bb81d9d1f86f24b5bedc5a49feb8b00c0c 100644 (file)
--- a/sound/core/seq/seq_virmidi.c
+++ b/sound/core/seq/seq_virmidi.c
@@ -174,12 +174,12 @@ static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream,
                        }
                        return;
                }
+               spin_lock_irqsave(&substream->runtime->lock, flags);
                if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
                        if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
-                               return;
+                               goto out;
                        vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
                }
-               spin_lock_irqsave(&substream->runtime->lock, flags);
                while (1) {
                        count = __snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
                        if (count <= 0)