From: Johan Hovold <johan@kernel.org>
Date: Thu, 16 Mar 2017 18:41:55 +0000 (-0700)
Subject: Input: kbtab - validate number of endpoints before using them
X-Git-Tag: v4.4.58~57
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3c4c0c470b58dd4a5e40e11ccd9fea7fbbfa799;p=thirdparty%2Fkernel%2Fstable.git

Input: kbtab - validate number of endpoints before using them

commit cb1b494663e037253337623bf1ef2df727883cb7 upstream.

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

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/kbtab.c b/drivers/input/tablet/kbtab.c
index d2ac7c2b5b828..2812f9236b7d0 100644
--- a/drivers/input/tablet/kbtab.c
+++ b/drivers/input/tablet/kbtab.c
@@ -122,6 +122,9 @@ static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *i
 	struct input_dev *input_dev;
 	int error = -ENOMEM;
 
+	if (intf->cur_altsetting->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	kbtab = kzalloc(sizeof(struct kbtab), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!kbtab || !input_dev)