From: Johan Hovold <johan@kernel.org>
Date: Thu, 16 Mar 2017 18:43:09 +0000 (-0700)
Subject: Input: sur40 - validate number of endpoints before using them
X-Git-Tag: v4.4.58~56
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=549993001e7de0553d85c9022dc41d5b3ff7d1ff;p=thirdparty%2Fkernel%2Fstable.git

Input: sur40 - validate number of endpoints before using them

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@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c
index 45b466e3bbe84..0146e2c746493 100644
--- a/drivers/input/touchscreen/sur40.c
+++ b/drivers/input/touchscreen/sur40.c
@@ -500,6 +500,9 @@ static int sur40_probe(struct usb_interface *interface,
 	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)