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Date:   Mon, 27 Nov 2023 09:19:00 +0100
From:   Florian Eckert <fe@dev.tdt.de>
To:     Lee Jones <lee@kernel.org>
Cc:     Greg KH <gregkh@linuxfoundation.org>,
        Eckert.Florian@googlemail.com, jirislaby@kernel.org, pavel@ucw.cz,
        kabel@kernel.org, u.kleine-koenig@pengutronix.de,
        m.brock@vanmierlo.com, linux-kernel@vger.kernel.org,
        linux-serial@vger.kernel.org, linux-leds@vger.kernel.org
Subject: Re: [Patch v8 2/6] leds: ledtrig-tty: free allocated ttyname buffer
 on deactivate
In-Reply-To: <20231127080436.GA1470173@google.com>
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 <2023112356-amount-undertook-cdb2@gregkh>
 <71eeb0fad7c6d2c4a407df34facee232@dev.tdt.de>
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On 2023-11-27 09:04, Lee Jones wrote:
> On Mon, 27 Nov 2023, Florian Eckert wrote:
> 
>> 
>> 
>> On 2023-11-23 15:06, Greg KH wrote:
>> > On Thu, Nov 09, 2023 at 09:50:34AM +0100, Florian Eckert wrote:
>> > > The ttyname buffer for the ledtrig_tty_data struct is allocated in the
>> > > sysfs ttyname_store() function. This buffer must be released on
>> > > trigger
>> > > deactivation. This was missing and is thus a memory leak.
>> > >
>> > > While we are at it, the tty handler in the ledtrig_tty_data struct
>> > > should
>> > > also be returned in case of the trigger deactivation call.
>> > >
>> > > Fixes: fd4a641ac88f ("leds: trigger: implement a tty trigger")
>> > > Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
>> > > Signed-off-by: Florian Eckert <fe@dev.tdt.de>
>> > > ---
>> > >  drivers/leds/trigger/ledtrig-tty.c | 4 ++++
>> > >  1 file changed, 4 insertions(+)
>> > >
>> > > diff --git a/drivers/leds/trigger/ledtrig-tty.c
>> > > b/drivers/leds/trigger/ledtrig-tty.c
>> > > index 8ae0d2d284af..3e69a7bde928 100644
>> > > --- a/drivers/leds/trigger/ledtrig-tty.c
>> > > +++ b/drivers/leds/trigger/ledtrig-tty.c
>> > > @@ -168,6 +168,10 @@ static void ledtrig_tty_deactivate(struct
>> > > led_classdev *led_cdev)
>> > >
>> > >  	cancel_delayed_work_sync(&trigger_data->dwork);
>> > >
>> > > +	kfree(trigger_data->ttyname);
>> > > +	tty_kref_put(trigger_data->tty);
>> > > +	trigger_data->tty = NULL;
>> > > +
>> >
>> > This should be a stand-alone patch with a proper cc: stable tag added as
>> > well so that it can be accepted now, as it is independent of this new
>> > feature you are adding.
>> 
>> I already send this to stable@vger.kernel.org [1].
>> The patch already got an 'Reviewed-by:' from Uwe [2].
> 
> But then you posted this submission which superseded it in my inbox.
> 
> Only the latest patch will be processed when this happens.

Thanks for the clarification, I wasn't aware of that.

> 
>> I hope I did everything right and it only slipped through?
>> 
>> I will omit the patch from the v9 patchset of 'ledtrig-tty'.
>> This patch set will come later today with your requested changes.
>> 
>> Links;
>> [1] 
>> https://lore.kernel.org/stable/20231106141205.3376954-1-fe@dev.tdt.de/
>> [2] 
>> https://lore.kernel.org/stable/20231106144914.bflq2jxejdxs6zjb@pengutronix.de/
>> 
>> Best regards
>> 
>> Florian