[alsa-devel] [PATCH 4/5] ALSA: usb-audio: deallocate memory objects in error path

[Takashi Sakamoto]

On Feb 21 2017 05:49, Takashi Iwai wrote:
> On Mon, 20 Feb 2017 21:09:20 +0100,
> Takashi Sakamoto wrote:
>>
>> Some functions for quirks of Tascam US-16x08 have memory leaks.
>>
>> This commit fixes the bugs.
>>
>> Fixes: d2bb390a2081 ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk")
>> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
>> ---
>>  sound/usb/mixer_us16x08.c | 27 ++++++++++++++++-----------
>>  1 file changed, 16 insertions(+), 11 deletions(-)
>>
>> diff --git a/sound/usb/mixer_us16x08.c b/sound/usb/mixer_us16x08.c
>> index 5dae63c..d34dd1c 100644
>> --- a/sound/usb/mixer_us16x08.c
>> +++ b/sound/usb/mixer_us16x08.c
>> @@ -1082,8 +1082,8 @@ static int add_new_ctl(struct usb_mixer_interface *mixer,
>>
>>  	kctl = snd_ctl_new1(ncontrol, elem);
>>  	if (!kctl) {
>> -		kfree(elem);
>> -		return -ENOMEM;
>> +		err = -ENOMEM;
>> +		goto end;
>>  	}
>>
>>  	kctl->private_free = freeer;
>> @@ -1092,11 +1092,12 @@ static int add_new_ctl(struct usb_mixer_interface *mixer,
>>
>>  	err = snd_usb_mixer_add_control(&elem->head, kctl);
>>  	if (err < 0)
>> -		return err;
>> +		goto end;
>>
>>  	if (elem_ret)
>>  		*elem_ret = elem;
>> -
>> +end:
>> +	kfree(elem);
>>  	return 0;
>
> This will release elem even for the success case, no?

Yes, it's my intension of this patch.

But it's wrong. The allocated memory objects are used for private data 
for each control element set. I didn't care of it...

Here, what I should fix is just for error path. I'll post revised 
version of this patch this night.


Thanks

Takashi Sakamoto