2015-02-08 15:24:35

by David Dueck

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

This fixes a potential null pointer dereference.

Signed-off-by: David Dueck <[email protected]>
---
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;
--
2.2.2

2015-02-08 16:03:55

by Sebastian Andrzej Siewior

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

On 02/08/2015 04:29 PM, David Dueck wrote:
> This fixes a potential null pointer dereference.
>
> Signed-off-by: David Dueck <[email protected]>

Acked-by: Sebastian Andrzej Siewior <[email protected]>
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