net: ethernet: rtsn: Fix a null pointer dereference in rtsn_probe()

Add check for the return value of rcar_gen4_ptp_alloc()
to prevent potential null pointer dereference.

Fixes: b0d3969 ("net: ethernet: rtsn: Add support for Renesas Ethernet-TSN")
Cc: [email protected]
Signed-off-by: Haoxiang Li <[email protected]>
Reviewed-by: Niklas Söderlund <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Haoxiang Li

drivers/net/ethernet/renesas/rtsn.c

@@ -1259,7 +1259,12 @@ static int rtsn_probe(struct platform_device *pdev)
 	priv = netdev_priv(ndev);
 	priv->pdev = pdev;
 	priv->ndev = ndev;
+
 	priv->ptp_priv = rcar_gen4_ptp_alloc(pdev);
+	if (!priv->ptp_priv) {
+		ret = -ENOMEM;
+		goto error_free;
+	}
 
 	spin_lock_init(&priv->lock);
 	platform_set_drvdata(pdev, priv);