Subject: [PATCH 27/34] hv_netvsc: disable NAPI before channel close

From: Stephen Hemminger <[email-masked]>
Date: Mon, 14 May 2018 15:32:15 -0700

[ Commit 8348e0460ab1473f06c8b824699dd2eed3c1979d upstream. ]

This makes sure that no CPU is still process packets when
the channel is closed.

Fixes: 76bb5db5c749 ("netvsc: fix use after free on module removal")
Signed-off-by: Stephen Hemminger <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/hyperv/netvsc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7e0eb99571af..a8789dc4fc9b 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -567,6 +567,10 @@ void netvsc_device_remove(struct hv_device *device)
 
 	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
 
+	/* And disassociate NAPI context from device */
+	for (i = 0; i < net_device->num_chn; i++)
+		netif_napi_del(&net_device->chan_table[i].napi);
+
 	/*
 	 * At this point, no one should be accessing net_device
 	 * except in here
@@ -578,10 +582,6 @@ void netvsc_device_remove(struct hv_device *device)
 
 	netvsc_teardown_gpadl(device, net_device);
 
-	/* And dissassociate NAPI context from device */
-	for (i = 0; i < net_device->num_chn; i++)
-		netif_napi_del(&net_device->chan_table[i].napi);
-
 	/* Release all resources */
 	free_netvsc_device_rcu(net_device);
 }
-- 
2.14.3