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

From: Sebastian Andrzej Siewior
Date: Sun Feb 08 2015 - 11:04:18 EST


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

Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
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
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