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References: <20200711070835.4855-1-navid.emamdoost@gmail.com> <s5htuye2zjn.wl-tiwai@suse.de>
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From:   Navid Emamdoost <navid.emamdoost@gmail.com>
Date:   Sat, 11 Jul 2020 13:16:16 -0500
Message-ID: <CAEkB2ESiSEt6Rhs7iyni7C79LEUSCiKvtfxXRHzHU+dmkSag0A@mail.gmail.com>
Subject: Re: [PATCH] ALSA: trident: Fix a memory leak in snd_trident_create
To:     Takashi Iwai <tiwai@suse.de>
Cc:     Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
        alsa-devel@alsa-project.org, LKML <linux-kernel@vger.kernel.org>,
        Navid Emamdoost <emamd001@umn.edu>, Kangjie Lu <kjlu@umn.edu>,
        Stephen McCamant <smccaman@umn.edu>
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On Sat, Jul 11, 2020 at 4:04 AM Takashi Iwai <tiwai@suse.de> wrote:
>
> On Sat, 11 Jul 2020 09:08:30 +0200,
> Navid Emamdoost wrote:
> >
> > In the implementation of snd_trident_create(), the allocated trident is
> > leaked if snd_trident_mixer() fails. Release via snd_trident_free().
>
> No, this patch would result in double-free.
>
> The manual release of trident object isn't needed once after it gets
> added via snd_device_new().  Then it'll be automatically released at
> the error path (via snd_trident_dev_free()).

Thanks for the clarification.

>
>
> thanks,
>
> Takashi
>
> >
> > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> > Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> > ---
> >  sound/pci/trident/trident_main.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/sound/pci/trident/trident_main.c b/sound/pci/trident/trident_main.c
> > index 6e50376163a2..e98c692f6aa9 100644
> > --- a/sound/pci/trident/trident_main.c
> > +++ b/sound/pci/trident/trident_main.c
> > @@ -3582,8 +3582,11 @@ int snd_trident_create(struct snd_card *card,
> >               return err;
> >       }
> >
> > -     if ((err = snd_trident_mixer(trident, pcm_spdif_device)) < 0)
> > +     err = snd_trident_mixer(trident, pcm_spdif_device);
> > +     if (err < 0) {
> > +             snd_trident_free(trident);
> >               return err;
> > +     }
> >
> >       /* initialise synth voices */
> >       for (i = 0; i < 64; i++) {
> > --
> > 2.17.1
> >


-- 
Navid.