From: Johan Hovold <johan@kernel.org>
Date: Thu, 16 Mar 2017 18:35:12 +0000 (-0700)
Subject: Input: cm109 - validate number of endpoints before using them
X-Git-Tag: v3.12.73~64
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ed47b5c903b9f509c0bd6fc0e4f1dc9bbc59c8c4;p=thirdparty%2Fkernel%2Fstable.git

Input: cm109 - validate number of endpoints before using them

commit ac2ee9ba953afe88f7a673e1c0c839227b1d7891 upstream.

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

Fixes: c04148f915e5 ("Input: add driver for USB VoIP phones with CM109...")
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/misc/cm109.c b/drivers/input/misc/cm109.c
index 9365535ba7f15..50a7faa504f72 100644
--- a/drivers/input/misc/cm109.c
+++ b/drivers/input/misc/cm109.c
@@ -675,6 +675,10 @@ static int cm109_usb_probe(struct usb_interface *intf,
 	int error = -ENOMEM;
 
 	interface = intf->cur_altsetting;
+
+	if (interface->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	endpoint = &interface->endpoint[0].desc;
 
 	if (!usb_endpoint_is_int_in(endpoint))