quoted

If register_netdev() fails, the error handling path of the probe will not
free the memory allocated by the previous airoha_metadata_dst_alloc() call
because port->dev->reg_state will not be NETREG_REGISTERED.

So, an explicit airoha_metadata_dst_free() call is needed in this case to
avoid a memory leak.

Fixes: af3cf757d5c9 ("net: airoha: Move DSA tag in DMA descriptor")
Signed-off-by: Christophe JAILLET <redacted>
---
Changes in v2:
   - New patch

Compile tested only.
---
  drivers/net/ethernet/airoha/airoha_eth.c | 10 +++++++++-
  1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 16c7896f931f..af8c4015938c 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c

@@ -2873,7 +2873,15 @@ static int airoha_alloc_gdm_port(struct airoha_eth *eth,
  	if (err)
  		return err;
  
-	return register_netdev(dev);
+	err = register_netdev(dev);
+	if (err)
+		goto free_metadata_dst;
+
+	return 0;
+
+free_metadata_dst:
+	airoha_metadata_dst_free(port);
+	return err;
  }
  
  static int airoha_probe(struct platform_device *pdev)

-- 
2.49.0

I have not tested it but I think the right fix here would be something like:

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index b1ca8322d4eb..33f8926bba25 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c

@@ -2996,10 +2996,12 @@ static int airoha_probe(struct platform_device *pdev)
  	for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
  		struct airoha_gdm_port *port = eth->ports[i];
  
-		if (port && port->dev->reg_state == NETREG_REGISTERED) {
+		if (!port)
+			continue;