[PATCH] device property: set fwnode->secondary to NULL in fwnode_init()

[Bartosz Golaszewski]

If a firmware node is allocated on the stack (for instance: temporary
software node whose life-time we control) or on the heap - but using a
non-zeroing allocation function - and initialized using fwnode_init(),
its secondary pointer will contain uninitalized memory which likely will
be neither NULL nor IS_ERR() and so may end up being dereferenced (for
example: in dev_to_swnode()). Set fwnode->secondary to NULL on
initialization.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 01bb86b380a3 ("driver core: Add fwnode_init()")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
---
 include/linux/fwnode.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 80b38fbf2121..31df7608737e 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -208,6 +208,7 @@ struct fwnode_operations {
 static inline void fwnode_init(struct fwnode_handle *fwnode,
 			       const struct fwnode_operations *ops)
 {
+	fwnode->secondary = NULL;
 	fwnode->ops = ops;
 	INIT_LIST_HEAD(&fwnode->consumers);
 	INIT_LIST_HEAD(&fwnode->suppliers);
-- 
2.47.3