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@walle.cc>
---
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

On Tue, Mar 29, 2022 at 12:03:50AM +0200, Michael Walle wrote:
> 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@walle.cc>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Hello:

This patch was applied to netdev/net.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Tue, 29 Mar 2022 00:03:50 +0200 you wrote:
> 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@walle.cc>
> ---
> 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()
> 
> [...]

Here is the summary with links:
  - [v2,net] net: lan966x: fix kernel oops on ioctl when I/F is down
    https://git.kernel.org/netdev/net/c/ad7da1ce5749

You are awesome, thank you!
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