net: mv643xx_eth: fix an OF node reference leak

Current implementation of mv643xx_eth_shared_of_add_port() calls
of_parse_phandle(), but does not release the refcount on error. Call
of_node_put() in the error path and in mv643xx_eth_shared_of_remove().

This bug was found by an experimental verification tool that I am
developing.

Fixes: 76723bc ("net: mv643xx_eth: add DT parsing support")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Link: https://patch.msgid.link/20241221081448.3313163-1-joe@pf.is.s.u-tokyo.ac.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: joehattori

drivers/net/ethernet/marvell/mv643xx_eth.c

@@ -2704,9 +2704,15 @@ static struct platform_device *port_platdev[3];
 
 static void mv643xx_eth_shared_of_remove(void)
 {
+	struct mv643xx_eth_platform_data *pd;
 	int n;
 
 	for (n = 0; n < 3; n++) {
+		if (!port_platdev[n])
+			continue;
+		pd = dev_get_platdata(&port_platdev[n]->dev);
+		if (pd)
+			of_node_put(pd->phy_node);
 		platform_device_del(port_platdev[n]);
 		port_platdev[n] = NULL;
 	}
@@ -2769,8 +2775,10 @@ static int mv643xx_eth_shared_of_add_port(struct platform_device *pdev,
 	}
 
 	ppdev = platform_device_alloc(MV643XX_ETH_NAME, dev_num);
-	if (!ppdev)
-		return -ENOMEM;
+	if (!ppdev) {
+		ret = -ENOMEM;
+		goto put_err;
+	}
 	ppdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 	ppdev->dev.of_node = pnp;
 
@@ -2792,6 +2800,8 @@ static int mv643xx_eth_shared_of_add_port(struct platform_device *pdev,
 
 port_err:
 	platform_device_put(ppdev);
+put_err:
+	of_node_put(ppd.phy_node);
 	return ret;
 }