2020-07-11 07:09:26

by Navid Emamdoost

Subject: [PATCH] ALSA: trident: Fix a memory leak in snd_trident_create

In the implementation of snd_trident_create(), the allocated trident is
leaked if snd_trident_mixer() fails. Release via snd_trident_free().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Navid Emamdoost <[email protected]>
---
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

2020-07-11 09:05:27

by Takashi Iwai

Subject: Re: [PATCH] ALSA: trident: Fix a memory leak in snd_trident_create

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,

Takashi

>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Navid Emamdoost <[email protected]>
> ---
> 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
>

2020-07-11 18:20:04

by Navid Emamdoost

Subject: Re: [PATCH] ALSA: trident: Fix a memory leak in snd_trident_create

On Sat, Jul 11, 2020 at 4:04 AM Takashi Iwai <[email protected]> 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 <[email protected]>
> > ---
> > 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.