[PATCH 4.2.y-ckt 281/305] net: phy: mdio-mux: Check return value of mdiobus_alloc()

From: Kamal Mostafa
Date: Fri Jan 15 2016 - 19:15:53 EST


4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Tobias Klauser <tklauser@xxxxxxxxxx>

commit 20b08e1a793d898f0f13040d5418ee0955f678cf upstream.

mdiobus_alloc() might return NULL, but its return value is not
checked in mdio_mux_init(). This could potentially lead to a NULL
pointer dereference. Fix it by checking the return value

Fixes: 0ca2997d1452 ("netdev/of/phy: Add MDIO bus multiplexer support.")
Signed-off-by: Tobias Klauser <tklauser@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/net/phy/mdio-mux.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
index 4d4d25e..ac8a823 100644
--- a/drivers/net/phy/mdio-mux.c
+++ b/drivers/net/phy/mdio-mux.c
@@ -148,9 +148,14 @@ int mdio_mux_init(struct device *dev,
}
cb->bus_number = v;
cb->parent = pb;
+
cb->mii_bus = mdiobus_alloc();
+ if (!cb->mii_bus) {
+ ret_val = -ENOMEM;
+ of_node_put(child_bus_node);
+ break;
+ }
cb->mii_bus->priv = cb;
-
cb->mii_bus->irq = cb->phy_irq;
cb->mii_bus->name = "mdio_mux";
snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%x.%x",
--
1.9.1