[PATCH 3/3] bus: stm32-rifsc: reject debugfs setup without match data

[Jiale Yao]

Platform driver_override can bind a device to this driver without a
matching OF entry. With debugfs enabled, of_device_get_match_data()
then returns NULL and the configuration dump dereferences the resource
name table.

Reject debugfs registration without match data before exposing the
configuration file.

Fixes: 3bae4748c1cdd ("bus: rifsc: add debugfs entry to dump the firewall configuration")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/bus/stm32_rifsc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/bus/stm32_rifsc.c b/drivers/bus/stm32_rifsc.c
index 19d10379dcef..dd008103b9c1 100644
--- a/drivers/bus/stm32_rifsc.c
+++ b/drivers/bus/stm32_rifsc.c
@@ -617,6 +617,8 @@ static int stm32_rifsc_register_debugfs(struct stm32_firewall_controller *rifsc_
 	rifsc_priv->nb_rimu = nb_rimu;
 	rifsc_priv->nb_risal = nb_risal;
 	rifsc_priv->res_names = of_device_get_match_data(rifsc_controller->dev);
+	if (!rifsc_priv->res_names)
+		return -ENODATA;
 
 	root = debugfs_lookup("stm32_firewall", NULL);
 	if (!root)
-- 
2.34.1