From: Oliver Neukum <oneukum@xxxxxxxx> commit 397430b50a363d8b7bdda00522123f82df6adc5e upstream. maxpacket of 0 makes no sense and oopses as we need to divide by it. Give up. V2: fixed typo in log and stylistic issues Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> Reported-by: syzbot+76bb1d34ffa0adc03baa@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Johan Hovold <johan@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211021122944.21816-1-oneukum@xxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/usb/usbnet.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1740,6 +1740,10 @@ usbnet_probe (struct usb_interface *udev if (!dev->rx_urb_size) dev->rx_urb_size = dev->hard_mtu; dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1); + if (dev->maxpacket == 0) { + /* that is a broken device */ + goto out4; + } /* let userspace know we have a random address */ if (ether_addr_equal(net->dev_addr, node_id))
