[PATCH v3 17/17] media: rc: Validate carrier range in LIRC_SET_REC_CARRIER ioctl

[Sean Young <sean@mess.org>]

Ensure that the low value of the carrier range is smaller than the
high value. This fixes an underflow in ite_set_rx_carrier_range().

Signed-off-by: Sean Young <sean@mess.org>
---
 drivers/media/rc/lirc_dev.c    | 2 ++
 drivers/media/rc/rc-loopback.c | 5 -----
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index 183f1939b941..d9b6ecca563f 100644
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -492,6 +492,8 @@ static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			ret = -ENOTTY;
 		else if (val <= 0)
 			ret = -EINVAL;
+		else if (fh->carrier_low && fh->carrier_low > val)
+			ret = -EINVAL;
 		else
 			ret = dev->s_rx_carrier_range(dev, fh->carrier_low,
 						      val);
diff --git a/drivers/media/rc/rc-loopback.c b/drivers/media/rc/rc-loopback.c
index 53d0540717b3..9d56e77c9351 100644
--- a/drivers/media/rc/rc-loopback.c
+++ b/drivers/media/rc/rc-loopback.c
@@ -74,11 +74,6 @@ static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
 {
 	struct loopback_dev *lodev = dev->priv;
 
-	if (min < 1 || min > max) {
-		dev_dbg(&dev->dev, "invalid rx carrier range %u to %u\n", min, max);
-		return -EINVAL;
-	}
-
 	dev_dbg(&dev->dev, "setting rx carrier range %u to %u\n", min, max);
 	lodev->rxcarriermin = min;
 	lodev->rxcarriermax = max;
-- 
2.55.0