[PATCH v3] net/ice: fix crash on closing representor ports

[Mingjin Ye <mingjinx.ye@intel.com>]

The data resource in struct rte_eth_dev is cleared and points to NULL
when the DCF port is closed.

If the DCF representor port is closed after the DCF port is closed,
a segmentation fault occurs because the representor port accesses
the data resource released by the DCF port.

This patch checks if the resource is present before accessing.

Fixes: 5674465a32c8 ("net/ice: add DCF VLAN handling")
Fixes: da9cdcd1f372 ("net/ice: fix crash on representor port closing")
Cc: stable@dpdk.org

Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
---
v3: New solution.
---
 drivers/net/ice/ice_dcf_vf_representor.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ice/ice_dcf_vf_representor.c b/drivers/net/ice/ice_dcf_vf_representor.c
index b9fcfc80ad..8c45e28f02 100644
--- a/drivers/net/ice/ice_dcf_vf_representor.c
+++ b/drivers/net/ice/ice_dcf_vf_representor.c
@@ -111,14 +111,16 @@ ice_dcf_vf_repr_link_update(__rte_unused struct rte_eth_dev *ethdev,
 static __rte_always_inline struct ice_dcf_hw *
 ice_dcf_vf_repr_hw(struct ice_dcf_vf_repr *repr)
 {
-	struct ice_dcf_adapter *dcf_adapter =
-			repr->dcf_eth_dev->data->dev_private;
+	struct rte_eth_dev_data *dcf_data = repr->dcf_eth_dev->data;
+	struct ice_dcf_adapter *dcf_adapter;
 
-	if (!dcf_adapter) {
+	if (!dcf_data || !dcf_data->dev_private) {
 		PMD_DRV_LOG(ERR, "DCF for VF representor has been released\n");
 		return NULL;
 	}
 
+	dcf_adapter = dcf_data->dev_private;
+
 	return &dcf_adapter->real_hw;
 }
 
-- 
2.25.1