From: Johan Hovold <johan@kernel.org>
Date: Thu, 16 Mar 2017 18:39:29 +0000 (-0700)
Subject: Input: hanwang - validate number of endpoints before using them
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~20^2~60
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0812c6855c89d905e34e88166570cae4a401b23a;p=firefly-linux-kernel-4.4.55.git

Input: hanwang - validate number of endpoints before using them

commit ba340d7b83703768ce566f53f857543359aa1b98 upstream.

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

Fixes: bba5394ad3bd ("Input: add support for Hanwang tablets")
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/tablet/hanwang.c b/drivers/input/tablet/hanwang.c
index cd852059b99e..df4bea96d7ed 100644
--- a/drivers/input/tablet/hanwang.c
+++ b/drivers/input/tablet/hanwang.c
@@ -340,6 +340,9 @@ static int hanwang_probe(struct usb_interface *intf, const struct usb_device_id
 	int error;
 	int i;
 
+	if (intf->cur_altsetting->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	hanwang = kzalloc(sizeof(struct hanwang), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!hanwang || !input_dev) {