2017-08-11 13:06:49

by Anton Vasilyev

Subject: [PATCH v3] ASoC: samsung: i2s: Null pointer dereference on samsung_i2s_remove

If (quirks & QUIRK_SEC_DAI == 0) then samsung_i2s_probe() doesn't allocate
sec_dai and pri_dai->sec_dai remains Null, but samsung_i2s_remove()
performs pri_dai->sec_dai dereference in any case.

The patch adds sec_dai check on Null before derefence at
samsung_i2s_remove().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Anton Vasilyev <[email protected]>
---
v2: Drop initialization of sec_dai by NULL at samsung_i2s_remove
as Sylwester Nawrocki suggest.
---
v3: Fix typo in the comment
---
sound/soc/samsung/i2s.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
index af3ba4d..6f896e3 100644
--- a/sound/soc/samsung/i2s.c
+++ b/sound/soc/samsung/i2s.c
@@ -1376,13 +1376,9 @@ static int samsung_i2s_probe(struct platform_device *pdev)

static int samsung_i2s_remove(struct platform_device *pdev)
{
- struct i2s_dai *pri_dai, *sec_dai;
+ struct i2s_dai *pri_dai;

pri_dai = dev_get_drvdata(&pdev->dev);
- sec_dai = pri_dai->sec_dai;
-
- pri_dai->sec_dai = NULL;
- sec_dai->pri_dai = NULL;

pm_runtime_get_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
--
2.7.4

2017-08-12 07:10:57

by Krzysztof Kozlowski

Subject: Re: [PATCH v3] ASoC: samsung: i2s: Null pointer dereference on samsung_i2s_remove

On Fri, Aug 11, 2017 at 04:06:23PM +0300, Anton Vasilyev wrote:
> If (quirks & QUIRK_SEC_DAI == 0) then samsung_i2s_probe() doesn't allocate
> sec_dai and pri_dai->sec_dai remains Null, but samsung_i2s_remove()
> performs pri_dai->sec_dai dereference in any case.
>
> The patch adds sec_dai check on Null before derefence at
> samsung_i2s_remove().

No, I think this patch does not any check.

Best regards,
Krzysztof


>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Anton Vasilyev <[email protected]>
> ---
> v2: Drop initialization of sec_dai by NULL at samsung_i2s_remove
> as Sylwester Nawrocki suggest.
> ---
> v3: Fix typo in the comment
> ---
> sound/soc/samsung/i2s.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c
> index af3ba4d..6f896e3 100644
> --- a/sound/soc/samsung/i2s.c
> +++ b/sound/soc/samsung/i2s.c
> @@ -1376,13 +1376,9 @@ static int samsung_i2s_probe(struct platform_device *pdev)
>
> static int samsung_i2s_remove(struct platform_device *pdev)
> {
> - struct i2s_dai *pri_dai, *sec_dai;
> + struct i2s_dai *pri_dai;
>
> pri_dai = dev_get_drvdata(&pdev->dev);
> - sec_dai = pri_dai->sec_dai;
> -
> - pri_dai->sec_dai = NULL;
> - sec_dai->pri_dai = NULL;
>
> pm_runtime_get_sync(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
> --
> 2.7.4
>