USB: wusbcore: fix NULL-deref at probe

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer or accessing memory beyond the endpoint array should a
malicious device lack the expected endpoints.

This specifically fixes the NULL-pointer dereference when probing HWA HC
devices.

Fixes: df3654236e31 ("wusb: add the Wire Adapter (WA) core")
Cc: stable <stable@vger.kernel.org>     # 2.6.28
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/wusbcore/wa-hc.c b/drivers/usb/wusbcore/wa-hc.c
index 252c7bd..d01496f 100644 (file)
--- a/drivers/usb/wusbcore/wa-hc.c
+++ b/drivers/usb/wusbcore/wa-hc.c
@@ -39,6 +39,9 @@ int wa_create(struct wahc *wa, struct usb_interface *iface,
        int result;
        struct device *dev = &iface->dev;
 
+       if (iface->cur_altsetting->desc.bNumEndpoints < 3)
+               return -ENODEV;
+
        result = wa_rpipes_create(wa);
        if (result < 0)
                goto error_rpipes_create;