[PATCH net-next, 2/4] hv_netvsc: Fix error handling in netvsc_attach()

[Haiyang Zhang]

If rndis_filter_open() fails, we need to remove the rndis device created
in earlier steps, before returning an error code. Otherwise, the retry of
netvsc_attach() from its callers will fail and hang.

Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
---
 drivers/net/hyperv/netvsc_drv.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 734e411..a14fc8e 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -982,7 +982,7 @@ static int netvsc_attach(struct net_device *ndev,
 	if (netif_running(ndev)) {
 		ret = rndis_filter_open(nvdev);
 		if (ret)
-			return ret;
+			goto err;
 
 		rdev = nvdev->extension;
 		if (!rdev->link_state)
@@ -990,6 +990,13 @@ static int netvsc_attach(struct net_device *ndev,
 	}
 
 	return 0;
+
+err:
+	netif_device_detach(ndev);
+
+	rndis_filter_device_remove(hdev, nvdev);
+
+	return ret;
 }
 
 static int netvsc_set_channels(struct net_device *net,
-- 
1.8.3.1