From: Haiyang Zhang <haiyangz@microsoft.com>
Date: Wed, 30 Oct 2019 15:32:13 +0000
Patch-mainline: v5.4-rc6
Subject: hv_netvsc: Fix error handling in netvsc_attach()
Git-commit: 719b85c336ed35565d0f3982269d6f684087bb00
References: git-fixes

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@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Olaf Hering <ohering@suse.de>
---
 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
--- 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,