From fc2fc4694a85effc0fc920997241f20c0775eb9e Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 24 Apr 2018 07:26:59 +0200 Subject: [PATCH] ALSA: seq: oss: Fix unbalanced use lock for synth MIDI device [ Upstream commit f5e94b4c6ebdabe0f602d796e0430180927521a0 ] When get_synthdev() is called for a MIDI device, it returns the fixed midi_synth_dev without the use refcounting. OTOH, the caller is supposed to unreference unconditionally after the usage, so this would lead to unbalanced refcount. This patch corrects the behavior and keep up the refcount balance also for the MIDI synth device. Cc: Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/seq/oss/seq_oss_synth.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/sound/core/seq/oss/seq_oss_synth.c b/sound/core/seq/oss/seq_oss_synth.c index f38cf91b4faf3..e30a43efb2ad8 100644 --- a/sound/core/seq/oss/seq_oss_synth.c +++ b/sound/core/seq/oss/seq_oss_synth.c @@ -363,10 +363,14 @@ get_synthdev(struct seq_oss_devinfo *dp, int dev) return NULL; if (! dp->synths[dev].opened) return NULL; - if (dp->synths[dev].is_midi) - return &midi_synth_dev; - if ((rec = get_sdev(dev)) == NULL) - return NULL; + if (dp->synths[dev].is_midi) { + rec = &midi_synth_dev; + snd_use_lock_use(&rec->use_lock); + } else { + rec = get_sdev(dev); + if (!rec) + return NULL; + } if (! rec->opened) { snd_use_lock_free(&rec->use_lock); return NULL; -- 2.50.1