USB: usb_driver_claim_interface: add sanity checking

Attacks that trick drivers into passing a NULL pointer
to usb_driver_claim_interface() using forged descriptors are
known. This thwarts them by sanity checking.

Signed-off-by: Oliver Neukum <ONeukum@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 56593a9a8726..2057d91d8336 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -502,11 +502,15 @@ static int usb_unbind_interface(struct device *dev)
 int usb_driver_claim_interface(struct usb_driver *driver,
                                 struct usb_interface *iface, void *priv)
 {
-        struct device *dev = &iface->dev;
+        struct device *dev;
         struct usb_device *udev;
         int retval = 0;
         int lpm_disable_error;
 
+        if (!iface)
+                return -ENODEV;
+
+        dev = &iface->dev;
         if (dev->driver)
                 return -EBUSY;