From: Dongliang Mu <mudongliangabcd@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: perex@perex.cz, tiwai@suse.com, alsa-devel@alsa-project.org,
linux-kernel <linux-kernel@vger.kernel.org>,
syzbot+08a7d8b51ea048a74ffb@syzkaller.appspotmail.com
Subject: Re: [PATCH] ALSA: control led: fix memory leak in snd_ctl_led_register
Date: Mon, 31 May 2021 11:03:36 +0800 [thread overview]
Message-ID: <CAD-N9QVjhDDJxRnNrDzwt05BNijr1o11nE8xjvq8GrakEJ8EuQ@mail.gmail.com> (raw)
In-Reply-To: <A622EB84-DC4A-47A4-A828-CE6D25DC92EB@gmail.com>
On Sat, May 29, 2021 at 5:35 AM 慕冬亮 <mudongliangabcd@gmail.com> wrote:
>
>
>
> > On May 28, 2021, at 10:05 PM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > On Fri, May 28, 2021 at 09:50:49PM +0800, Dongliang Mu wrote:
> >>
> >> Can you please give some advise on how to fix this WARN issue?
> >
> > But it feels like it spoils the fun if I write the commit... Anyway:
>
> It’s fine. I am still in the learning process. It’s also good to learn experience by comparing your patch and my patch.
>
> >
> > regards,
> > dan carpenter
> >
> > diff --git a/sound/core/control_led.c b/sound/core/control_led.c
> > index 25f57c14f294..dd357abc1b58 100644
> > --- a/sound/core/control_led.c
> > +++ b/sound/core/control_led.c
> > @@ -740,6 +740,7 @@ static int __init snd_ctl_led_init(void)
> > for (; group > 0; group--) {
> > led = &snd_ctl_leds[group - 1];
> > device_del(&led->dev);
> > + device_put(&led->dev);
> > }
> > device_del(&snd_ctl_led_dev);
> > return -ENOMEM;
> > @@ -768,6 +769,7 @@ static void __exit snd_ctl_led_exit(void)
> > for (group = 0; group < MAX_LED; group++) {
> > led = &snd_ctl_leds[group];
> > device_del(&led->dev);
> > + device_put(&led->dev);
> > }
> > device_del(&snd_ctl_led_dev);
> > snd_ctl_led_clean(NULL);
Hi Dan,
I tried this patch, and it still triggers the memleak. My
understanding is that the device object is already freed in the
snd_ctl_led_sysfs_remove.
>
> Does this patch mean I should add device_put in the init and exit function other than snd_ctl_led_sysfs_remove? This will cause device_release bypass the release method checking?
>
next prev parent reply other threads:[~2021-05-31 3:04 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-28 13:17 [PATCH] ALSA: control led: fix memory leak in snd_ctl_led_register Dongliang Mu
2021-05-28 13:33 ` Dan Carpenter
2021-05-28 13:50 ` Dongliang Mu
2021-05-28 14:05 ` Dan Carpenter
2021-05-28 21:35 ` 慕冬亮
2021-05-31 3:03 ` Dongliang Mu [this message]
2021-05-31 4:40 ` Dan Carpenter
2021-05-31 6:20 ` Dongliang Mu
2021-05-31 7:03 ` Dan Carpenter
2021-05-31 7:34 ` Dongliang Mu
2021-05-31 8:08 ` Dongliang Mu
2021-05-31 8:46 ` Dan Carpenter
2021-05-31 9:10 ` Dongliang Mu
2021-05-31 9:38 ` Dan Carpenter
2021-05-31 10:35 ` Dongliang Mu
2021-05-31 10:43 ` Dan Carpenter
2021-05-31 10:59 ` Dongliang Mu
2021-05-31 8:12 ` Dan Carpenter
2021-05-31 4:36 ` Dan Carpenter
2021-05-31 11:01 ` Dan Carpenter
2021-05-31 11:07 ` Dan Carpenter
2021-05-31 11:11 ` Dongliang Mu
2021-06-01 13:17 ` Dongliang Mu
2021-06-01 13:46 ` Dan Carpenter
2021-06-01 14:19 ` Dongliang Mu
2021-06-01 14:43 ` Dan Carpenter
2021-06-01 15:52 ` Dongliang Mu
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