[PATCH v4 net] net: airoha: Fix an error handling path in airoha_alloc_gdm_port()

[Christophe JAILLET]

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 <christophe.jaillet at wanadoo.fr>
Acked-by: Lorenzo Bianconi <lorenzo at kernel.org>
Reviewed-by: Simon Horman <horms at kernel.org>
---
Changes in v4:
  - Add A-b and R-b tags
  - Rebase against latest -next (because v3 now gets "Hunk #1 succeeded
    at 2869 (offset -4 lines)")

Changes in v3:
  - None
v3: https://lore.kernel.org/all/5c94b9b345017f29ed653e2f05d25620d128c3f0.1746715755.git.christophe.jaillet@wanadoo.fr/

Changes in v2:
  - New patch
v2: https://lore.kernel.org/all/5c94b9b3850f7f29ed653e2205325620df28c3ff.1746715755.git.christophe.jaillet@wanadoo.fr/

Compile tested only.

In the previous iteration, this patch was part of a serie. But it
should be related to 'net', while the rest of the serie was for
'net-next'. So it is resent as a stand-alone patch, as a v4.

---
 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
@@ -2869,7 +2869,15 @@ 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