[PATCH 4.9 27/88] Input: cm109 - validate number of endpoints before using them

From: Greg Kroah-Hartman
Date: Tue Mar 28 2017 - 08:43:18 EST


4.9-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
@@ -700,6 +700,10 @@ 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))