[PATCH AUTOSEL 4.14 247/371] net: pasemi: fix an use-after-free in pasemi_mac_phy_init()

Sasha Levin
2020-01-16T17:28:24Z

From: Wen Yang <wen.yang99@zte.com.cn>

[ Upstream commit faf5577f2498cea23011b5c785ef853ded22700b ]

The phy_dn variable is still being used in of_phy_connect() after the
of_node_put() call, which may result in use-after-free.

Fixes: 1dd2d06c0459 ("net: Rework pasemi_mac driver to use of_mdio infrastructure")
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/pasemi/pasemi_mac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/pasemi/pasemi_mac.c b/drivers/net/ethernet/pasemi/pasemi_mac.c
index 49591d9c2e1b..c9b4ac9d3330 100644
--- a/drivers/net/ethernet/pasemi/pasemi_mac.c
+++ b/drivers/net/ethernet/pasemi/pasemi_mac.c
@@ -1053,7 +1053,6 @@ static int pasemi_mac_phy_init(struct net_device *dev)

dn = pci_device_to_OF_node(mac->pdev);
phy_dn = of_parse_phandle(dn, "phy-handle", 0);
- of_node_put(phy_dn);

mac->link = 0;
mac->speed = 0;
@@ -1062,6 +1061,7 @@ static int pasemi_mac_phy_init(struct net_device *dev)
phydev = of_phy_connect(dev, phy_dn, &pasemi_adjust_link, 0,
PHY_INTERFACE_MODE_SGMII);

+ of_node_put(phy_dn);
if (!phydev) {
printk(KERN_ERR "%s: Could not attach to phy\n", dev->name);
return -ENODEV;
--
2.20.1