Subject: [PATCH 2/2 net] net: mvpp2: cls: Prevent buffer overflow in mvpp2_ethtool_cls_rule_del()

From: Dan Carpenter <[email-masked]>
Date: Wed, 6 May 2020 13:16:56 +0300

The "info->fs.location" is a u32 that comes from the user via the
ethtool_set_rxnfc() function.  We need to check for invalid values to
prevent a buffer overflow.

I copy and pasted this check from the mvpp2_ethtool_cls_rule_ins()
function.

Fixes: 90b509b39ac9 ("net: mvpp2: cls: Add Classification offload support")
Signed-off-by: Dan Carpenter <[email-masked]>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c
index 8972cdd559e85..7352244c5e68b 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c
@@ -1428,6 +1428,9 @@ int mvpp2_ethtool_cls_rule_del(struct mvpp2_port *port,
 	struct mvpp2_ethtool_fs *efs;
 	int ret;
 
+	if (info->fs.location >= MVPP2_N_RFS_ENTRIES_PER_FLOW)
+		return -EINVAL;
+
 	efs = port->rfs_rules[info->fs.location];
 	if (!efs)
 		return -EINVAL;
-- 
2.26.2