[PATCH net-next v2 3/3] net: pcs: rzn1-miic: Validate dtb configuration values

[Kyle Hendry via B4 Relay <devnull+khendry.reliablecontrols.com@kernel.org>]

From: Kyle Hendry <khendry@reliablecontrols.com>

Bad configuration values from the dtb could result in out of bounds array
access. Verify parsed values are within range for the SoC and fail the
probe if invalid.

Signed-off-by: Kyle Hendry <khendry@reliablecontrols.com>
---
 drivers/net/pcs/pcs-rzn1-miic.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/net/pcs/pcs-rzn1-miic.c b/drivers/net/pcs/pcs-rzn1-miic.c
index 9e830932ce49..9a4c6d3b7d42 100644
--- a/drivers/net/pcs/pcs-rzn1-miic.c
+++ b/drivers/net/pcs/pcs-rzn1-miic.c
@@ -697,9 +697,25 @@ static int miic_parse_dt(struct miic *miic, u32 *mode_cfg)
 		if (of_property_read_u32(conv, "reg", &port))
 			continue;
 
+		if (port < miic->of_data->miic_port_start ||
+		    port > miic->of_data->miic_port_max) {
+			dev_err(miic->dev, "Port number out of range: %d\n", port);
+			of_node_put(conv);
+			ret = -EINVAL;
+			goto err;
+		}
+
 		if (of_property_read_u32(conv, "renesas,miic-input", &conf))
 			continue;
 
+		if (conf >= miic->of_data->conf_to_string_count) {
+			dev_err(miic->dev, "Port %d configuration out of range: %d\n",
+				port, conf);
+			of_node_put(conv);
+			ret = -EINVAL;
+			goto err;
+		}
+
 		/* Adjust for 0 based index */
 		dt_val[port + !miic->of_data->miic_port_start] = conf;
 
@@ -709,6 +725,7 @@ static int miic_parse_dt(struct miic *miic, u32 *mode_cfg)
 	}
 
 	ret = miic_match_dt_conf(miic, dt_val, mode_cfg);
+err:
 	kfree(dt_val);
 
 	return ret;

-- 
2.43.0