[3.19.y-ckt stable] Patch "Input: gtco - fix crash on detecting device without endpoints" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    Input: gtco - fix crash on detecting device without endpoints

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt20.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From af7fad325a0b7a59e35e0dc2694422424410e6dd Mon Sep 17 00:00:00 2001
From: Vladis Dronov <vdronov at redhat.com>
Date: Thu, 31 Mar 2016 10:53:42 -0700
Subject: Input: gtco - fix crash on detecting device without endpoints

commit 162f98dea487206d9ab79fc12ed64700667a894d upstream.

The gtco driver expects at least one valid endpoint. If given malicious
descriptors that specify 0 for the number of endpoints, it will crash in
the probe function. Ensure there is at least one endpoint on the interface
before using it.

Also let's fix a minor coding style issue.

The full correct report of this issue can be found in the public
Red Hat Bugzilla:

https://bugzilla.redhat.com/show_bug.cgi?id=1283385

Reported-by: Ralf Spenneberg <ralf at spenneberg.net>
Signed-off-by: Vladis Dronov <vdronov at redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/input/tablet/gtco.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/input/tablet/gtco.c b/drivers/input/tablet/gtco.c
index 8580456..a51de54 100644
--- a/drivers/input/tablet/gtco.c
+++ b/drivers/input/tablet/gtco.c
@@ -868,6 +868,14 @@ static int gtco_probe(struct usb_interface *usbinterface,
 		goto err_free_buf;
 	}

+	/* Sanity check that a device has an endpoint */
+	if (usbinterface->altsetting[0].desc.bNumEndpoints < 1) {
+		dev_err(&usbinterface->dev,
+			"Invalid number of endpoints\n");
+		error = -EINVAL;
+		goto err_free_urb;
+	}
+
 	/*
 	 * The endpoint is always altsetting 0, we know this since we know
 	 * this device only has one interrupt endpoint
@@ -889,7 +897,7 @@ static int gtco_probe(struct usb_interface *usbinterface,
 	 * HID report descriptor
 	 */
 	if (usb_get_extra_descriptor(usbinterface->cur_altsetting,
-				     HID_DEVICE_TYPE, &hid_desc) != 0){
+				     HID_DEVICE_TYPE, &hid_desc) != 0) {
 		dev_err(&usbinterface->dev,
 			"Can't retrieve exta USB descriptor to get hid report descriptor length\n");
 		error = -EIO;
--
2.7.4