pinctrl: intel: platform: fix error path in device_for_each_child_node()

JIRA: https://issues.redhat.com/browse/RHEL-66957
CVE: CVE-2024-50197

commit 16a6d2e
Author: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Date:   Thu Sep 26 16:11:02 2024 +0200

    pinctrl: intel: platform: fix error path in device_for_each_child_node()

    The device_for_each_child_node() loop requires calls to
    fwnode_handle_put() upon early returns to decrement the refcount of
    the child node and avoid leaking memory if that error path is triggered.

    There is one early returns within that loop in
    intel_platform_pinctrl_prepare_community(), but fwnode_handle_put() is
    missing.

    Instead of adding the missing call, the scoped version of the loop can
    be used to simplify the code and avoid mistakes in the future if new
    early returns are added, as the child node is only used for parsing, and
    it is never assigned.

    Cc: stable@vger.kernel.org
    Fixes: c5860e4 ("pinctrl: intel: Add a generic Intel pin control platform driver")
    Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
    Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
    Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Signed-off-by: Steve Best <sbest@redhat.com>

Author: sfbest

drivers/pinctrl/intel/pinctrl-intel-platform.c

@@ -90,7 +90,6 @@ static int intel_platform_pinctrl_prepare_community(struct device *dev,
 						    struct intel_community *community,
 						    struct intel_platform_pins *pins)
 {
-	struct fwnode_handle *child;
 	struct intel_padgroup *gpps;
 	unsigned int group;
 	size_t ngpps;
@@ -131,7 +130,7 @@ static int intel_platform_pinctrl_prepare_community(struct device *dev,
 		return -ENOMEM;
 
 	group = 0;
-	device_for_each_child_node(dev, child) {
+	device_for_each_child_node_scoped(dev, child) {
 		struct intel_padgroup *gpp = &gpps[group];
 
 		gpp->reg_num = group;