[PATCH] USB: OHCI: Check the overrides pointer for NULL in ohci_init_driver()

[Tomasz Figa <tomasz.figa@gmail.com>]

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@gmail.com>
---
 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);
 
-- 
1.8.3.2