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* [PATCH] pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error.
@ 2014-08-18  9:08 Xiubo Li
  2014-08-25 12:38 ` Thierry Reding
  0 siblings, 1 reply; 2+ messages in thread
From: Xiubo Li @ 2014-08-18  9:08 UTC (permalink / raw)
  To: thierry.reding, linux-pwm; +Cc: Xiubo Li

Since we cannot make sure the 'chip->npwm' will always be none zero here,
and then if either equal to zero, the kzalloc() will return ZERO_SIZE_PTR,
which equals to ((void *)16).

So this patch fix this with just doing the zero check before calling kzalloc().

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
---
 drivers/pwm/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 4b66bf0..786d0f1 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -236,7 +236,7 @@ int pwmchip_add(struct pwm_chip *chip)
 	int ret;
 
 	if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
-	    !chip->ops->enable || !chip->ops->disable)
+	    !chip->ops->enable || !chip->ops->disable || !chip->npwm)
 		return -EINVAL;
 
 	mutex_lock(&pwm_lock);
-- 
1.8.5


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error.
  2014-08-18  9:08 [PATCH] pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error Xiubo Li
@ 2014-08-25 12:38 ` Thierry Reding
  0 siblings, 0 replies; 2+ messages in thread
From: Thierry Reding @ 2014-08-25 12:38 UTC (permalink / raw)
  To: Xiubo Li; +Cc: linux-pwm

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On Mon, Aug 18, 2014 at 05:08:44PM +0800, Xiubo Li wrote:
> Since we cannot make sure the 'chip->npwm' will always be none zero here,
> and then if either equal to zero, the kzalloc() will return ZERO_SIZE_PTR,
> which equals to ((void *)16).
> 
> So this patch fix this with just doing the zero check before calling kzalloc().
> 
> Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
> ---
>  drivers/pwm/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.

Thierry

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^ permalink raw reply	[flat|nested] 2+ messages in thread

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2014-08-18  9:08 [PATCH] pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error Xiubo Li
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