[PATCH net] net: stmmac: fix invalid call to mdiobus_get_phy()

From: Heiner Kallweit <hkallweit1@gmail.com>
To: Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	David Miller <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: [PATCH net] net: stmmac: fix invalid call to mdiobus_get_phy()
Date: Sun, 15 Jan 2023 18:24:08 +0100	[thread overview]
Message-ID: <669f9671-ecd1-a41b-2727-7b73e3003985@gmail.com> (raw)

In a number of cases the driver assigns a default value of -1 to
priv->plat->phy_addr. This may result in calling mdiobus_get_phy()
with addr parameter being -1. Therefore check for this scenario and
bail out before calling mdiobus_get_phy().

Fixes: 42e87024f727 ("net: stmmac: Fix case when PHY handle is not present")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c6951c976..b7e5af58a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1150,6 +1150,11 @@ static int stmmac_init_phy(struct net_device *dev)
 		int addr = priv->plat->phy_addr;
 		struct phy_device *phydev;
 
+		if (addr < 0) {
+			netdev_err(priv->dev, "no phy found\n");
+			return -ENODEV;
+		}
+
 		phydev = mdiobus_get_phy(priv->mii, addr);
 		if (!phydev) {
 			netdev_err(priv->dev, "no phy at addr %d\n", addr);
-- 
2.39.0

