Re: [PATCH 7/7] mfd: max8998: Fix possible NULL pointer dereference on i2c_new_dummy error

[Lee Jones]

On Tue, 11 Feb 2014, Krzysztof Kozlowski wrote:

> During probe the driver allocates dummy I2C device for RTC with i2c_new_dummy() but it does not check the return value of this call.
> 
> In case of error (i2c_new_device(): memory allocation failure or I2C
> address cannot be used) this function returns NULL which is later used
> by i2c_unregister_device().
> 
> If i2c_new_dummy() fails for RTC device, fail also the probe for
> main MFD driver.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
>  drivers/mfd/max8998.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mfd/max8998.c b/drivers/mfd/max8998.c
> index 612ca404e150..61ea1826f8b4 100644
> --- a/drivers/mfd/max8998.c
> +++ b/drivers/mfd/max8998.c
> @@ -215,6 +215,10 @@ static int max8998_i2c_probe(struct i2c_client *i2c,
>  	mutex_init(&max8998->iolock);
>  
>  	max8998->rtc = i2c_new_dummy(i2c->adapter, RTC_I2C_ADDR);
> +	if (!max8998->rtc) {
> +		dev_err(&i2c->dev, "Failed to allocate I2C device for RTC\n");
> +		return -ENODEV;
> +	}
>  	i2c_set_clientdata(max8998->rtc, max8998);
>  
>  	max8998_irq_init(max8998);

Applied, thanks.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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