net: qcom/emac: fix UAF in emac_remove

commit ad297cd2db8953e2202970e9504cab247b6c7cb4 upstream.

adpt is netdev private data and it cannot be
used after free_netdev() call. Using adpt after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() at the end of the
function.

Fixes: 54e19bc74f33 ("net: qcom/emac: do not use devm on internal phy pdev")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c
index 8543bf3c348408adeb6f44d3306eaa7e22fa7c5b..ad655f0a4965ce87c60e9784262d88a774420879 100644 (file)
--- a/drivers/net/ethernet/qualcomm/emac/emac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac.c
@@ -735,12 +735,13 @@ static int emac_remove(struct platform_device *pdev)
 
        put_device(&adpt->phydev->mdio.dev);
        mdiobus_unregister(adpt->mii_bus);
-       free_netdev(netdev);
 
        if (adpt->phy.digital)
                iounmap(adpt->phy.digital);
        iounmap(adpt->phy.base);
 
+       free_netdev(netdev);
+
        return 0;
 }