[PATCH net-next 03/11] net: stmmac: fix PTP error cleanup in __stmmac_open()

[Russell King (Oracle)]

The cleanup function for stmmac_setup_ptp() is stmmac_release_ptp()
which entirely undoes the effects of stmmac_setup_ptp() by
unregistering the PTP device and then stopping the PTP clock,
whereas stmmac_hw_teardown() will only stop the PTP clock while
leaving the PTP device registered.

This can lead to a kernel oops - if __stmmac_open() fails after
registering the PTP clock, the PTP device will remain registered,
and if the module is removed, subsequent PTP device accesses will
lead to a kernel oops.

Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 5d76cf7957ab..167405aac5b8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4032,7 +4032,7 @@ static int __stmmac_open(struct net_device *dev,
 	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 		hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 
-	stmmac_hw_teardown(dev);
+	stmmac_release_ptp(priv);
 init_error:
 	phylink_disconnect_phy(priv->phylink);
 init_phy_error:
-- 
2.47.3