staging: vchiq_arm: Fix missing refcount decrement in error path for fw_node

An error path was introduced without including the required call to
of_node_put() to decrement the node's refcount and avoid leaking memory.
If the call to kzalloc() for 'mgmt' fails, the probe returns without
decrementing the refcount.

Use the automatic cleanup facility to fix the bug and protect the code
against new error paths where the call to of_node_put() might be missing
again.

Cc: stable@vger.kernel.org
Fixes: 1c9e16b73166 ("staging: vc04_services: vchiq_arm: Split driver static and runtime data")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Link: https://lore.kernel.org/r/20241014-vchiq_arm-of_node_put-v2-2-cafe0a4c2666@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index ba57bfe614f68939b9555b2b0a8db0e62a4226c3..af623ad87c1507c3998781ebc1f34dd00b462bad 100644 (file)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -1328,7 +1328,6 @@ MODULE_DEVICE_TABLE(of, vchiq_of_match);
 
 static int vchiq_probe(struct platform_device *pdev)
 {
-       struct device_node *fw_node;
        const struct vchiq_platform_info *info;
        struct vchiq_drv_mgmt *mgmt;
        int ret;
@@ -1337,8 +1336,8 @@ static int vchiq_probe(struct platform_device *pdev)
        if (!info)
                return -EINVAL;
 
-       fw_node = of_find_compatible_node(NULL, NULL,
-                                         "raspberrypi,bcm2835-firmware");
+       struct device_node *fw_node __free(device_node) =
+               of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware");
        if (!fw_node) {
                dev_err(&pdev->dev, "Missing firmware node\n");
                return -ENOENT;
@@ -1349,7 +1348,6 @@ static int vchiq_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        mgmt->fw = devm_rpi_firmware_get(&pdev->dev, fw_node);
-       of_node_put(fw_node);
        if (!mgmt->fw)
                return -EPROBE_DEFER;