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 <mremski@mutualink.net>
Tested-by: Mike Remski <mremski@mutualink.net>
Cc: <stable@vger.kernel.org> # 2.6.31
Signed-off-by: Johan Hovold <johan@kernel.org>
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index edf3b12..115662c1 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1566,14 +1566,17 @@
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
