From foo@baz Sat 16 May 2020 02:04:40 PM CEST
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 8 May 2020 17:37:20 +0300
Subject: dpaa2-eth: prevent array underflow in update_cls_rule()

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 6d32a5119811d2e9b5caa284181944c6f1f192ed ]

The "location" is controlled by the user via the ethtool_set_rxnfc()
function.  This update_cls_rule() function checks for array overflows
but it doesn't check if the value is negative.  I have changed the type
to unsigned to prevent array underflows.

Fixes: afb90dbb5f78 ("dpaa2-eth: Add ethtool support for flow classification")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
@@ -625,7 +625,7 @@ static int num_rules(struct dpaa2_eth_pr
 
 static int update_cls_rule(struct net_device *net_dev,
 			   struct ethtool_rx_flow_spec *new_fs,
-			   int location)
+			   unsigned int location)
 {
 	struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
 	struct dpaa2_eth_cls_rule *rule;