[PATCH 3/4] HID: logitech-hidpp: add boundary check for name retrieval

From: Peter Wu <peter@lekensteyn.nl>
To: Benjamin Tissoires <benjamin.tissoires@redhat.com>,
	Jiri Kosina <jkosina@suse.cz>,
	Nestor Lopez Casado <nlopezcasad@logitech.com>
Cc: Peter Hutterer <peter.hutterer@who-t.net>,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] HID: logitech-hidpp: add boundary check for name retrieval
Date: Thu, 11 Dec 2014 13:51:19 +0100	[thread overview]
Message-ID: <1418302280-14794-4-git-send-email-peter@lekensteyn.nl> (raw)
In-Reply-To: <1418302280-14794-1-git-send-email-peter@lekensteyn.nl>

The HID response has a limited size. Do not trust the value returned by
hardware, check that it really fits in the message.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>
---
 drivers/hid/hid-logitech-hidpp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 4d72c20..4292cc3 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -313,6 +313,9 @@ static char *hidpp_get_unifying_name(struct hidpp_device *hidpp_dev)
 
 	len = response.rap.params[1];
 
+	if (2 + len > sizeof(response.rap.params))
+		return NULL;
+
 	name = kzalloc(len + 1, GFP_KERNEL);
 	if (!name)
 		return NULL;
-- 
2.1.3

