[RFC PATCH 2/3] core: platform: fix an invalid kfree during of_platform_depopulate

[Suman Anna]

Drivers can use of_platform_populate() to create platform devices
for children of the device main node, and a complementary API
of_platform_depopulate() is provided to delete these child devices.
Any platform_data supplied for the OF devices through auxdata lookup
data is populated directly in the device's platform_data field, unlike
those created using platform API. The of_platform_depopulate()
leverages the platform code for cleanup, and this will result in a
kernel oops due to an invalid kfree on this direct populated
platform_data.

Fix this by resetting the platform data for OF devices during
platform device cleanup.

Signed-off-by: Suman Anna <s-anna at ti.com>
---
 drivers/base/platform.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 9421fed40905..129e69c8c894 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -200,6 +200,8 @@ static void platform_device_release(struct device *dev)
 	struct platform_object *pa = container_of(dev, struct platform_object,
 						  pdev.dev);
 
+	if (pa->pdev.dev.of_node)
+		pa->pdev.dev.platform_data = NULL;
 	of_device_node_put(&pa->pdev.dev);
 	kfree(pa->pdev.dev.platform_data);
 	kfree(pa->pdev.mfd_cell);
-- 
2.2.1