net: phy: smsc: bail out in lan87xx_read_status if genphy_read_status fails

[ Upstream commit c22c3bbf351e4ce905f082649cffa1ff893ea8c1 ]

If genphy_read_status fails then further access to the PHY may result
in unpredictable behavior. To prevent this bail out immediately if
genphy_read_status fails.

Fixes: 4223dbffed9f ("net: phy: smsc: Re-enable EDPD mode for LAN87xx")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/026aa4f2-36f5-1c10-ab9f-cdb17dda6ac4@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index 04e628788f1b58da11fd7b10b65128d66fb8aea9..36dcf6c7f445d0fb1d0932c31d92513e57b3c97d 100644 (file)
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -206,8 +206,11 @@ static int lan95xx_config_aneg_ext(struct phy_device *phydev)
 static int lan87xx_read_status(struct phy_device *phydev)
 {
        struct smsc_phy_priv *priv = phydev->priv;
+       int err;
 
-       int err = genphy_read_status(phydev);
+       err = genphy_read_status(phydev);
+       if (err)
+               return err;
 
        if (!phydev->link && priv->energy_enable && phydev->irq == PHY_POLL) {
                /* Disable EDPD to wake up PHY */