[PATCH 3.12 090/142] uwb: hwa-rc: fix NULL-deref at probe

[Jiri Slaby]

From: Johan Hovold <johan@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

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@xxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/uwb/hwa-rc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/uwb/hwa-rc.c b/drivers/uwb/hwa-rc.c
index 0257f35cfb9d..e75bbe5a10cd 100644
--- a/drivers/uwb/hwa-rc.c
+++ b/drivers/uwb/hwa-rc.c
@@ -825,6 +825,9 @@ 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) {
-- 
2.12.2