[PATCH v3 4/6] net/netvsc: fix event callback leak on rxfilter failure

[Long Li]

In hn_dev_start(), if hn_rndis_set_rxfilter() fails after registering
the device event callback, the function returns without unregistering
the callback. Unregister it before returning on error.

Fixes: 4e9c73e96e83 ("net/netvsc: add Hyper-V network device")
Cc: sta...@dpdk.org
Signed-off-by: Long Li <lon...@microsoft.com>
---
v3: New patch.
---
 drivers/net/netvsc/hn_ethdev.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/netvsc/hn_ethdev.c b/drivers/net/netvsc/hn_ethdev.c
index 19721b4829..5e954b8812 100644
--- a/drivers/net/netvsc/hn_ethdev.c
+++ b/drivers/net/netvsc/hn_ethdev.c
@@ -1043,16 +1043,22 @@ hn_dev_start(struct rte_eth_dev *dev)
                                      NDIS_PACKET_TYPE_BROADCAST |
                                      NDIS_PACKET_TYPE_ALL_MULTICAST |
                                      NDIS_PACKET_TYPE_DIRECTED);
-       if (error)
+       if (error) {
+               rte_dev_event_callback_unregister(NULL,
+                                                 netvsc_hotadd_callback, hv);
                return error;
+       }
 
        error = hn_vf_start(dev);
-       if (error)
+       if (error) {
                hn_rndis_set_rxfilter(hv, 0);
+               rte_dev_event_callback_unregister(NULL,
+                                                 netvsc_hotadd_callback, hv);
+               return error;
+       }
 
        /* Initialize Link state */
-       if (error == 0)
-               hn_dev_link_update(dev, 0);
+       hn_dev_link_update(dev, 0);
 
        for (i = 0; i < hv->num_queues; i++) {
                dev->data->tx_queue_state[i] = RTE_ETH_QUEUE_STATE_STARTED;
-- 
2.43.0