Re: [RFT v2 1/3] ASoC: samsung: Fix possible double iounmap on s3c24xx driver probe failure

[Arvind Yadav <arvind.yadav.cs@gmail.com>]

On Thursday 27 July 2017 10:43 PM, Krzysztof Kozlowski wrote:
> Commit 87b132bc0315 ("ASoC: samsung: s3c24{xx,12}-i2s: port to use
> generic dmaengine API") moved ioremap() call from
> s3c-i2s-v2.c:s3c_i2sv2_probe() to s3c2412-i2s.c:s3c2412_iis_dev_probe()
> and converted it to devm- resource managed interface.
>
> However the error path in first of them - s3c_i2sv2_probe() - was not
> updated.  If getting a iis clock in s3c_i2sv2_probe() failed, the
> address space would be unmapped there.  This could lead to:
> 1. double iounmap() later from devm-interface of s3c2412_iis_dev_probe()),
> 2. accessing the memory by other functions in s3c2412-i2s.c unit.
>
> Anyway, the owner of this mapped region should be s3c2412-i2s.c because
> it starts the mapping.
>
> Affected are drivers for S3C24xx family although issue was not reproduced.
>
> Fixes: 87b132bc0315 ("ASoC: samsung: s3c24{xx,12}-i2s: port to use generic dmaengine API")
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Arvind Yadav<arvind.yadav.cs@gmail.com>
> ---
>
> Not marking as Cc-stable because this is theoretical problem, not
> reproduced and also not tested.
>
> Please, kindly test on S3C24xx hardware.
>
> Changes since v1:
> 1. None
> ---
>   sound/soc/samsung/s3c-i2s-v2.c | 1 -
>   1 file changed, 1 deletion(-)
>
> diff --git a/sound/soc/samsung/s3c-i2s-v2.c b/sound/soc/samsung/s3c-i2s-v2.c
> index ca522a95160b..9b28046eea8e 100644
> --- a/sound/soc/samsung/s3c-i2s-v2.c
> +++ b/sound/soc/samsung/s3c-i2s-v2.c
> @@ -634,7 +634,6 @@ int s3c_i2sv2_probe(struct snd_soc_dai *dai,
>   	i2s->iis_pclk = clk_get(dev, "iis");
>   	if (IS_ERR(i2s->iis_pclk)) {
>   		dev_err(dev, "failed to get iis_clock\n");
> -		iounmap(i2s->regs);
>   		return -ENOENT;
>   	}
>