Re: [PATCH] USB: OHCI: Check the overrides pointer for NULL inohci_init_driver()

From: Alan Stern
Date: Sat Sep 28 2013 - 23:00:32 EST


On Sat, 28 Sep 2013, Tomasz Figa wrote:

> A series of commit starting at
>
> 50a97e059b USB: OHCI: make ohci-exynos a separate driver
>
> and ending at
>
> b8ad5c3706 USB: OHCI: make ohci-pxa27x a separate driver
>
> introduced the concept of separate OHCI drivers for particular
> controllers. Respective drivers need to call ohci_init_driver() to
> initialize hc_driver struct with generic data and to certain extent
> with platform specific overrides through ohci_driver_overrides struct
> passed as second argument to this function. However the code does not
> check if the ohci_driver_overrides struct pointer is non-NULL, which
> leads for a NULL pointer dereference for drivers that do not need any
> overrides.
>
> This patch fixes the problem by dereferencing the passed pointer to
> ohci_driver_overrides struct only if it is non-NULL.
>
> Signed-off-by: Tomasz Figa <tomasz.figa@xxxxxxxxx>
> ---
> drivers/usb/host/ohci-hcd.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
> index 21d937a..8ada13f 100644
> --- a/drivers/usb/host/ohci-hcd.c
> +++ b/drivers/usb/host/ohci-hcd.c
> @@ -1161,10 +1161,12 @@ void ohci_init_driver(struct hc_driver *drv,
> /* Copy the generic table to drv and then apply the overrides */
> *drv = ohci_hc_driver;
>
> - drv->product_desc = over->product_desc;
> - drv->hcd_priv_size += over->extra_priv_size;
> - if (over->reset)
> - drv->reset = over->reset;
> + if (over) {
> + drv->product_desc = over->product_desc;
> + drv->hcd_priv_size += over->extra_priv_size;
> + if (over->reset)
> + drv->reset = over->reset;
> + }
> }
> EXPORT_SYMBOL_GPL(ohci_init_driver);

You were scooped by Kevin Hilman:

http://marc.info/?l=linux-usb&m=138029463906143&w=2

Alan Stern

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