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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Haiyang Zhang <haiyangz@microsoft.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 112/125] hv_netvsc: Fix error handling in netvsc_attach()
Date:   Mon, 11 Nov 2019 19:29:11 +0100
Message-Id: <20191111181454.792993510@linuxfoundation.org>
In-Reply-To: <20191111181438.945353076@linuxfoundation.org>
References: <20191111181438.945353076@linuxfoundation.org>
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From: Haiyang Zhang <haiyangz@microsoft.com>

[ Upstream commit 719b85c336ed35565d0f3982269d6f684087bb00 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 6f6c0dbd91fc8..b7a71c203aa37 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -993,7 +993,7 @@ 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)
@@ -1001,6 +1001,13 @@ 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,
-- 
2.20.1