[PATCH 2/2] device property: fix for a case of use-after-free

[Heikki Krogerus]

In device_remove_property_set(), if the primary fwnode is
of type "pset", it has to be set pointing to NULL before
calling set_secondary_fwnode(). Otherwise
set_secondary_fwnode() will attempt to set the
fwnode->secondary member after the fwnode has been freed.

Reported-by: John Youn <John.Youn@xxxxxxxxxxxx>
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
 drivers/base/property.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index a163f2c..ddf2987 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -820,7 +820,9 @@ void device_remove_property_set(struct device *dev)
 	 * the pset. If there is no real firmware node (ACPI/DT) primary
 	 * will hold the pset.
 	 */
-	if (!is_pset_node(fwnode))
+	if (is_pset_node(fwnode))
+		dev->fwnode = NULL;
+	else
 		fwnode = fwnode->secondary;
 	if (!IS_ERR(fwnode) && is_pset_node(fwnode))
 		pset_free_set(to_pset_node(fwnode));
-- 
2.7.0