From 25379bf8bc4d4e83bd74d823048b85a95ae5a521 Mon Sep 17 00:00:00 2001
From: Sean Young <sean@mess.org>
Date: Mon, 8 Jul 2013 17:33:11 -0300
Subject: [media] lirc: validate transmission ir data

The lirc interface allows 255 u32 spaces and pulses, which are usec. If
the driver can handle this (e.g. winbond-cir) you can produce hours of
meaningless IR data and there is no method of interrupting it.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
---
 drivers/media/rc/ir-lirc-codec.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

(limited to 'drivers')

diff --git a/drivers/media/rc/ir-lirc-codec.c b/drivers/media/rc/ir-lirc-codec.c
index e4561264e124..e5be920c0599 100644
--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -140,11 +140,20 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 		goto out;
 	}
 
+	for (i = 0; i < count; i++) {
+		if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		duration += txbuf[i];
+	}
+
 	ret = dev->tx_ir(dev, txbuf, count);
 	if (ret < 0)
 		goto out;
 
-	for (i = 0; i < ret; i++)
+	for (duration = i = 0; i < ret; i++)
 		duration += txbuf[i];
 
 	ret *= sizeof(unsigned int);
-- 
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