uwb: hwa-rc: fix NULL-deref at probe

BugLink: http://bugs.launchpad.net/bugs/1677589
commit daf229b15907fbfdb6ee183aac8ca428cb57e361 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack endpoints.

Note that the dereference happens in the start callback which is called
during probe.

Fixes: de520b8bd552 ("uwb: add HWA radio controller driver")
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/uwb/hwa-rc.c b/drivers/uwb/hwa-rc.c
index 0aa6c3c29d17260f684b8bf79944eff43af04427..35a1e777b4497ad0ad1cfa18db0834354732b128 100644 (file)
--- a/drivers/uwb/hwa-rc.c
+++ b/drivers/uwb/hwa-rc.c
@@ -823,6 +823,9 @@ static int hwarc_probe(struct usb_interface *iface,
        struct hwarc *hwarc;
        struct device *dev = &iface->dev;
 
+       if (iface->cur_altsetting->desc.bNumEndpoints < 1)
+               return -ENODEV;
+
        result = -ENOMEM;
        uwb_rc = uwb_rc_alloc();
        if (uwb_rc == NULL) {