hyperv: Move wait completion msg code into rndis_filter_halt_device()

We need to wait for send_completion msg before put_rndis_request() at
the end of rndis_filter_halt_device(). Otherwise, netvsc_send_completion()
may reference freed memory which is overwritten, and cause panic.

Reported-by: Long Li <longli@microsoft.com>
Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 7 deletions

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 6cee2917eb02..4a1a5f58fa73 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -383,13 +383,6 @@ int netvsc_device_remove(struct hv_device *device)
         unsigned long flags;
 
         net_device = hv_get_drvdata(device);
-        spin_lock_irqsave(&device->channel->inbound_lock, flags);
-        net_device->destroy = true;
-        spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
-
-        /* Wait for all send completions */
-        wait_event(net_device->wait_drain,
-                   atomic_read(&net_device->num_outstanding_sends) == 0);
 
         netvsc_disconnect_vsp(net_device);
 
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index e5d6146937fa..1e88a1095934 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -718,6 +718,9 @@ static void rndis_filter_halt_device(struct rndis_device *dev)
 {
         struct rndis_request *request;
         struct rndis_halt_request *halt;
+        struct netvsc_device *nvdev = dev->net_dev;
+        struct hv_device *hdev = nvdev->dev;
+        ulong flags;
 
         /* Attempt to do a rndis device halt */
         request = get_rndis_request(dev, RNDIS_MSG_HALT,
@@ -735,6 +738,14 @@ static void rndis_filter_halt_device(struct rndis_device *dev)
         dev->state = RNDIS_DEV_UNINITIALIZED;
 
 cleanup:
+        spin_lock_irqsave(&hdev->channel->inbound_lock, flags);
+        nvdev->destroy = true;
+        spin_unlock_irqrestore(&hdev->channel->inbound_lock, flags);
+
+        /* Wait for all send completions */
+        wait_event(nvdev->wait_drain,
+                atomic_read(&nvdev->num_outstanding_sends) == 0);
+
         if (request)
                 put_rndis_request(dev, request);
         return;