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Date:   Mon, 10 Aug 2020 08:58:09 +0200
Message-ID: <s5h5z9r6l8e.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Dinghao Liu <dinghao.liu@zju.edu.cn>
Cc:     kjlu@umn.edu, Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Eliot Blennerhassett <eblennerhassett@audioscience.com>,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ALSA: pci/asihpi: Fix memory leak in snd_card_asihpi_capture_open()
In-Reply-To: <20200810063957.13692-1-dinghao.liu@zju.edu.cn>
References: <20200810063957.13692-1-dinghao.liu@zju.edu.cn>
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On Mon, 10 Aug 2020 08:39:55 +0200,
Dinghao Liu wrote:
> 
> When snd_pcm_hw_constraint_pow2() fails, dpcm should be freed
> just like when hpi_instream_open()  fails.

It will be cleaned up via runtime->private_free call in the caller
side (snd_pcm_open -> snd_pcm_release_substream ->
snd_pcm_detach_substream), hence this would result in double-free.


thanks,

Takashi

> 
> Fixes: 719f82d3987aa ("ALSA: Add support of AudioScience ASI boards")
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>  sound/pci/asihpi/asihpi.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/pci/asihpi/asihpi.c b/sound/pci/asihpi/asihpi.c
> index 023c35a2a951..736eceacd3d0 100644
> --- a/sound/pci/asihpi/asihpi.c
> +++ b/sound/pci/asihpi/asihpi.c
> @@ -1244,8 +1244,10 @@ static int snd_card_asihpi_capture_open(struct snd_pcm_substream *substream)
>  	if (card->can_dma)
>  		err = snd_pcm_hw_constraint_pow2(runtime, 0,
>  					SNDRV_PCM_HW_PARAM_BUFFER_BYTES);
> -	if (err < 0)
> +	if (err < 0) {
> +		kfree(dpcm);
>  		return err;
> +	}
>  
>  	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
>  		card->update_interval_frames);
> -- 
> 2.17.1
>