[PATCH v2 3/4] software node: verify that property data is not on stack

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

When registering a software node, ensure that the property data is not
located on the stack, as it is expected to persist for the lifetime of
the node.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/base/swnode.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 51320837f3a9..286eab02e8fb 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -16,6 +16,7 @@
 #include <linux/kstrtox.h>
 #include <linux/list.h>
 #include <linux/property.h>
+#include <linux/sched/task_stack.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
@@ -917,6 +918,7 @@ EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
 int software_node_register(const struct software_node *node)
 {
 	struct swnode *parent = software_node_to_swnode(node->parent);
+	const struct property_entry *prop;
 
 	if (software_node_to_swnode(node))
 		return -EEXIST;
@@ -924,6 +926,14 @@ int software_node_register(const struct software_node *node)
 	if (node->parent && !parent)
 		return -EINVAL;
 
+	for (prop = node->properties; prop && prop->name; prop++) {
+		if (!prop->is_inline && object_is_on_stack(prop->pointer)) {
+			pr_err("%s: property data can't be on stack ('%s')\n",
+			       __func__, prop->name);
+			return -EINVAL;
+		}
+	}
+
 	return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
 }
 EXPORT_SYMBOL_GPL(software_node_register);

-- 
2.53.0.1018.g2bb0e51243-goog