From: Sean Young <sean@mess.org>
Date: Sun, 8 Oct 2017 18:18:52 +0000 (-0400)
Subject: media: rc: check for integer overflow
X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~7^2~1130
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/%22mailto:kde%40ewsoftware.de//%22style.css/%22/%22http:/www.example.com/%22mailto:kde%40ewsoftware.de/%22style.css/%22?a=commitdiff_plain;h=bcd2dc9e329b3cf76cda88732f09aac4157fc5da;p=linux-4.9.git

media: rc: check for integer overflow

commit 3e45067f94bbd61dec0619b1c32744eb0de480c8 upstream.

The ioctl LIRC_SET_REC_TIMEOUT would set a timeout of 704ns if called
with a timeout of 4294968us.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/media/rc/ir-lirc-codec.c b/drivers/media/rc/ir-lirc-codec.c
index b49f80cb49c9..d9a5710532f4 100644
--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -286,11 +286,14 @@ static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 		if (!dev->max_timeout)
 			return -ENOSYS;
 
+		/* Check for multiply overflow */
+		if (val > U32_MAX / 1000)
+			return -EINVAL;
+
 		tmp = val * 1000;
 
-		if (tmp < dev->min_timeout ||
-		    tmp > dev->max_timeout)
-				return -EINVAL;
+		if (tmp < dev->min_timeout || tmp > dev->max_timeout)
+			return -EINVAL;
 
 		if (dev->s_timeout)
 			ret = dev->s_timeout(dev, tmp);