[PATCH net v3 4/4] net: wan: fsl_ucc_hdlc: release HDLC device on remove

[Myeonghun Pak <mhun512@gmail.com>]

ucc_hdlc_probe() registers an HDLC netdev whose private pointer refers to
the separately allocated ucc_hdlc_private object. The remove path frees
that object and its resources without unregistering or freeing the
netdev. The registered device is left with a dangling private pointer.

Unregister the HDLC device before releasing the UCC and DMA resources so
an active interface is stopped first. Free the netdev before releasing
its private object.

This patch depends on the preceding "net: wan: hdlc: close active devices
before protocol detach" fix (patch 3 of this series). Without that fix,
protocol detach clears IFF_UP before unregister can invoke ndo_stop, so
an active interface would not be stopped before its resources are freed.

Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20260803133048.42650-1-mhun512@gmail.com
Link: https://lore.kernel.org/r/20260806020541.2011936-2-kuba@kernel.org
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
 drivers/net/wan/fsl_ucc_hdlc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 596f4ef053636..371150efc1a65 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -1255,6 +1255,8 @@ static void ucc_hdlc_remove(struct platform_device *pdev)
 {
 	struct ucc_hdlc_private *priv = dev_get_drvdata(&pdev->dev);
 
+	unregister_hdlc_device(priv->ndev);
+
 	uhdlc_memclean(priv);
 
 	if (priv->utdm && priv->utdm->si_regs) {
@@ -1266,6 +1268,7 @@ static void ucc_hdlc_remove(struct platform_device *pdev)
 		iounmap(priv->utdm->siram);
 		priv->utdm->siram = NULL;
 	}
+	free_netdev(priv->ndev);
 	kfree(priv);
 
 	dev_info(&pdev->dev, "UCC based hdlc module removed\n");
-- 
2.47.1