length, sglen and vary are unsigned, so cannot be negative
see
vi drivers/usb/misc/usbtest.c +18
struct usbtest_param {
...
        unsigned                iterations;
        unsigned                length;
        unsigned                vary;
        unsigned                sglen;
...
};
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
        if (code != USBTEST_REQUEST)
                return -EOPNOTSUPP;
 
-       if (param->iterations <= 0 || param->length < 0
-                       || param->sglen < 0 || param->vary < 0)
+       if (param->iterations <= 0)
                return -EINVAL;
 
        if (mutex_lock_interruptible(&dev->lock))