[PATCH] net: dsa: mv88e6xxx: fix netdev reference leak on remove

[Guangshuo Li <lgs201920130244@gmail.com>]

mv88e6xxx_probe() uses the referenced network device provided through
platform data, but the remove path does not drop the corresponding
reference.

The probe failure path correctly calls dev_put() for pdata->netdev.
However, after a successful probe, mv88e6xxx_remove() tears down the
switch resources without releasing this reference, leaving the network
device reference count unbalanced after driver removal.

Call dev_put() in mv88e6xxx_remove() after the switch resources have
been torn down.

This issue was found by manual code inspection.

Fixes: 877b7cb0b6f2 ("net: dsa: mv88e6xxx: Add minimal platform_data support")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/net/dsa/mv88e6xxx/chip.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 80b877c74513..e4394af2a3a2 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -7464,6 +7464,7 @@ static int mv88e6xxx_probe(struct mdio_device *mdiodev)
 
 static void mv88e6xxx_remove(struct mdio_device *mdiodev)
 {
+	struct dsa_mv88e6xxx_pdata *pdata = mdiodev->dev.platform_data;
 	struct dsa_switch *ds = dev_get_drvdata(&mdiodev->dev);
 	struct mv88e6xxx_chip *chip;
 
@@ -7486,6 +7487,9 @@ static void mv88e6xxx_remove(struct mdio_device *mdiodev)
 		mv88e6xxx_irq_poll_free(chip);
 
 	mv88e6xxx_phy_destroy(chip);
+
+	if (pdata)
+		dev_put(pdata->netdev);
 }
 
 static void mv88e6xxx_shutdown(struct mdio_device *mdiodev)
-- 
2.43.0