[PATCH v2 net] net: lan966x: fix kernel oops on ioctl when I/F is down

From: Michael Walle
Date: Mon Mar 28 2022 - 18:12:38 EST


ioctls handled by phy_mii_ioctl() will cause a kernel oops when the
interface is down. Fix it by making sure there is a PHY attached.

Fixes: 735fec995b21 ("net: lan966x: Implement SIOCSHWTSTAMP and SIOCGHWTSTAMP")
Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
changes since v1:
- reword commit message
- test for the presence of phydev instead of the interface state
- move the test just before phy_mii_ioctl()

drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index ec42e526f6fb..1759b0e2b56f 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -408,6 +408,9 @@ static int lan966x_port_ioctl(struct net_device *dev, struct ifreq *ifr,
}
}

+ if (!dev->phydev)
+ return -ENODEV;
+
return phy_mii_ioctl(dev->phydev, ifr, cmd);
}

--
2.30.2