From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: [PATCH 1/8] ALSA: seq: oss: Fix unbalanced use lock for synth MIDI device Date: Tue, 24 Apr 2018 09:56:12 +0200 Message-ID: <20180424075619.29602-2-tiwai@suse.de> References: <20180424075619.29602-1-tiwai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id E2EA226766D for ; Tue, 24 Apr 2018 09:56:42 +0200 (CEST) In-Reply-To: <20180424075619.29602-1-tiwai@suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org Cc: Dan Carpenter List-Id: alsa-devel@alsa-project.org 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 --- 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 cd0e0ebbfdb1..9e2b250ae780 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; -- 2.16.3