From: Johan Hovold Date: Thu, 5 Jun 2014 14:05:52 +0000 (+0200) Subject: USB: ftdi_sio: fix null deref at port probe X-Git-Tag: firefly_0821_release~176^2~3665^2~4^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=aea1ae8760314e072bf1b773521e9de5d5dda10d;p=firefly-linux-kernel-4.4.55.git USB: ftdi_sio: fix null deref at port probe Fix NULL-pointer dereference when probing an interface with no endpoints. These devices have two bulk endpoints per interface, but this avoids crashing the kernel if a user forces a non-FTDI device to be probed. Note that the iterator variable was made unsigned in order to avoid a maybe-uninitialized compiler warning for ep_desc after the loop. Fixes: 895f28badce9 ("USB: ftdi_sio: fix hi-speed device packet size calculation") Reported-by: Mike Remski Tested-by: Mike Remski Cc: # 2.6.31 Signed-off-by: Johan Hovold --- diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index edf3b124583c..115662c16dcc 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1566,14 +1566,17 @@ static void ftdi_set_max_packet_size(struct usb_serial_port *port) struct usb_device *udev = serial->dev; struct usb_interface *interface = serial->interface; - struct usb_endpoint_descriptor *ep_desc = &interface->cur_altsetting->endpoint[1].desc; + struct usb_endpoint_descriptor *ep_desc; unsigned num_endpoints; - int i; + unsigned i; num_endpoints = interface->cur_altsetting->desc.bNumEndpoints; dev_info(&udev->dev, "Number of endpoints %d\n", num_endpoints); + if (!num_endpoints) + return; + /* NOTE: some customers have programmed FT232R/FT245R devices * with an endpoint size of 0 - not good. In this case, we * want to override the endpoint descriptor setting and use a