[PATCH] net: dpaa2: ptp: fix device node reference leak on remove

[Guangshuo Li]

dpaa2_ptp_probe() gets a referenced device node with
of_find_compatible_node() and stores it in dev->of_node.

The probe failure paths release this reference with of_node_put().
However, after a successful probe, dpaa2_ptp_remove() tears down the
PTP and MC resources without dropping the device node reference.

Release dev->of_node during driver removal and clear the pointer after
dropping the reference.

This issue was found by manual code inspection.

Fixes: d346c9e86d86 ("dpaa2-ptp: reuse ptp_qoriq driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-ptp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ptp.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ptp.c
index 4497e3c0456d..440319a1e775 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ptp.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ptp.c
@@ -232,6 +232,8 @@ static void dpaa2_ptp_remove(struct fsl_mc_device *mc_dev)
 	fsl_mc_free_irqs(mc_dev);
 	dprtc_close(mc_dev->mc_io, 0, mc_dev->mc_handle);
 	fsl_mc_portal_free(mc_dev->mc_io);
+	of_node_put(dev->of_node);
+	dev->of_node = NULL;
 }
 
 static const struct fsl_mc_device_id dpaa2_ptp_match_id_table[] = {
-- 
2.43.0