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: v3.12.73~66
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=006c02072edb31b1a0668946a93d425fffba61c9;p=thirdparty%2Fkernel%2Fstable.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: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/drivers/input/tablet/hanwang.c b/drivers/input/tablet/hanwang.c
index 5cc04124995c4..263c85e72e14a 100644
--- a/drivers/input/tablet/hanwang.c
+++ b/drivers/input/tablet/hanwang.c
@@ -341,6 +341,9 @@ 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) {