[RFC PATCH] i2c: acpi: put device when verifying client fails

[Wolfram Sang <wsa@the-dreams.de>]

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

i2c_verify_client() can fail, so we need to put the device when that
happens.

Fixes: 525e6fabeae2 ("i2c / ACPI: add support for ACPI reconfigure notifications")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

RFC because I don't know if it can be that the returned dev is not an
i2c_client. Yet, since it can happen theoretically, I think we should
have the checks.

 drivers/i2c/i2c-core-acpi.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 8f3dbc97a057..8b0ff780919b 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -394,9 +394,17 @@ EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 {
 	struct device *dev;
+	struct i2c_client *client;
 
 	dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
-	return dev ? i2c_verify_client(dev) : NULL;
+	if (!dev)
+		return NULL;
+
+	client = i2c_verify_client(dev);
+	if (!client)
+		put_device(dev);
+
+	return client;
 }
 
 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
-- 
2.20.1