From: Jiri Kosina <jkosina@suse.cz>
Date: Wed, 27 Aug 2014 07:13:15 +0000 (+0200)
Subject: HID: picolcd: sanity check report size in raw_event() callback
X-Git-Tag: firefly_0821_release~176^2~3133^2~3
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=844817e47eef14141cf59b8d5ac08dd11c0a9189;p=firefly-linux-kernel-4.4.55.git

HID: picolcd: sanity check report size in raw_event() callback

The report passed to us from transport driver could potentially be
arbitrarily large, therefore we better sanity-check it so that raw_data
that we hold in picolcd_pending structure are always kept within proper
bounds.

Cc: stable@vger.kernel.org
Reported-by: Steven Vittitoe <scvitti@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
---

diff --git a/drivers/hid/hid-picolcd_core.c b/drivers/hid/hid-picolcd_core.c
index acbb021065ec..020df3c2e8b4 100644
--- a/drivers/hid/hid-picolcd_core.c
+++ b/drivers/hid/hid-picolcd_core.c
@@ -350,6 +350,12 @@ static int picolcd_raw_event(struct hid_device *hdev,
 	if (!data)
 		return 1;
 
+	if (size > 64) {
+		hid_warn(hdev, "invalid size value (%d) for picolcd raw event\n",
+				size);
+		return 0;
+	}
+
 	if (report->id == REPORT_KEY_STATE) {
 		if (data->input_keys)
 			ret = picolcd_raw_keypad(data, report, raw_data+1, size-1);