Re: [PATCH 3/7] mfd: max77686: Fix possible NULL pointer dereference on i2c_new_dummy error

From: Lee Jones
Date: Tue Feb 11 2014 - 07:22:46 EST


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/max77686.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mfd/max77686.c b/drivers/mfd/max77686.c
> index f53d5823a3f7..e5fce765accb 100644
> --- a/drivers/mfd/max77686.c
> +++ b/drivers/mfd/max77686.c
> @@ -121,6 +121,10 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
> dev_info(max77686->dev, "device found\n");
>
> max77686->rtc = i2c_new_dummy(i2c->adapter, I2C_ADDR_RTC);
> + if (!max77686->rtc) {
> + dev_err(max77686->dev, "Failed to allocate I2C device for RTC\n");
> + return -ENODEV;
> + }
> i2c_set_clientdata(max77686->rtc, max77686);
>
> max77686_irq_init(max77686);

Applied, thanks.

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/