[PATCH 4.9 63/94] regulator: fix crash caused by null driver data

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yu Zhao <yuzhao@xxxxxxxxxx>

commit fb6de923ca3358a91525552b4907d4cb38730bdd upstream.

dev_set_drvdata() needs to be called before device_register()
exposes device to userspace. Otherwise kernel crashes after it
gets null pointer from dev_get_drvdata() when userspace tries
to access sysfs entries.

[Removed backtrace for length -- broonie]

Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/regulator/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -4054,13 +4054,13 @@ regulator_register(const struct regulato
 	    !rdev->desc->fixed_uV)
 		rdev->is_switch = true;
 
+	dev_set_drvdata(&rdev->dev, rdev);
 	ret = device_register(&rdev->dev);
 	if (ret != 0) {
 		put_device(&rdev->dev);
 		goto unset_supplies;
 	}
 
-	dev_set_drvdata(&rdev->dev, rdev);
 	rdev_init_debugfs(rdev);
 
 	/* try to resolve regulators supply since a new one was registered */