[PATCH 3.18 082/124] Input: cm109 - validate number of endpoints before using them

From: Greg Kroah-Hartman
Date: Thu Apr 20 2017 - 02:41:34 EST


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

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit ac2ee9ba953afe88f7a673e1c0c839227b1d7891 upstream.

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

Fixes: c04148f915e5 ("Input: add driver for USB VoIP phones with CM109...")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/input/misc/cm109.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/input/misc/cm109.c
+++ b/drivers/input/misc/cm109.c
@@ -675,6 +675,10 @@ static int cm109_usb_probe(struct usb_in
int error = -ENOMEM;

interface = intf->cur_altsetting;
+
+ if (interface->desc.bNumEndpoints < 1)
+ return -ENODEV;
+
endpoint = &interface->endpoint[0].desc;

if (!usb_endpoint_is_int_in(endpoint))