hv_netvsc: disable NAPI before channel close

[ 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 <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7e0eb99..a8789dc 100644 (file)
--- 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);
 }