Return an error if hub->descriptor->bNbrPorts==0. Without this additional
check, we can end up doing a "hub->ports = kzalloc(0, GFP_KERNEL)".
This hub->ports pointer will therefore be non-NULL and will be used.
Example of dmesg:
INIT: usb 1-1: New USB device found, idVendor=0424, idProduct=2512
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
hub 1-1:1.0: USB hub found
version 2.86 bootinghub 1-1:1.0: 0 ports detected
Unable to handle kernel NULL pointer dereference at virtual address 00000010
Signed-off-by: David Linares <dlinares.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>