Re: [PATCH] usb: phy: am335x-control: check return value of bus_find_device

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 02/08/2015 04:29 PM, David Dueck wrote:
> This fixes a potential null pointer dereference.
> 
> Signed-off-by: David Dueck <davidcdueck@googlemail.com>

Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: d4332013919a ("driver core: dev_get_drvdata: Don't check for NULL
dev")

Greg, this is a regression since d43320139 ("driver core:
dev_get_drvdata: Don't check for NULL dev"). I didn't check for NULL
after bus_find_device() because I knew that dev_get_drvdata() will do
it.

> ---
>  drivers/usb/phy/phy-am335x-control.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/usb/phy/phy-am335x-control.c b/drivers/usb/phy/phy-am335x-control.c
> index 403fab7..7b3035f 100644
> --- a/drivers/usb/phy/phy-am335x-control.c
> +++ b/drivers/usb/phy/phy-am335x-control.c
> @@ -126,6 +126,9 @@ struct phy_control *am335x_get_phy_control(struct device *dev)
>  		return NULL;
>  
>  	dev = bus_find_device(&platform_bus_type, NULL, node, match);
> +	if (!dev)
> +		return NULL;
> +
>  	ctrl_usb = dev_get_drvdata(dev)
>  	if (!ctrl_usb)
>  		return NULL;
> 

Sebastian