[PATCH 3.18 084/124] Input: sur40 - validate number of endpoints before using them

From: Greg Kroah-Hartman
Date: Thu Apr 20 2017 - 02:40:12 EST


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

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

From: Johan Hovold <johan@xxxxxxxxxx>

commit 92461f5d723037530c1f36cce93640770037812c upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer or accessing memory that lie beyond the end of the endpoint
array should a malicious device lack the expected endpoints.

Fixes: bdb5c57f209c ("Input: add sur40 driver for Samsung SUR40... ")
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/touchscreen/sur40.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/input/touchscreen/sur40.c
+++ b/drivers/input/touchscreen/sur40.c
@@ -361,6 +361,9 @@ static int sur40_probe(struct usb_interf
if (iface_desc->desc.bInterfaceClass != 0xFF)
return -ENODEV;

+ if (iface_desc->desc.bNumEndpoints < 5)
+ return -ENODEV;
+
/* Use endpoint #4 (0x86). */
endpoint = &iface_desc->endpoint[4].desc;
if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)