xen-netback: Fix vif->disable handling

In the patch called "xen-netback: Turn off the carrier if the guest is not able
to receive" new branches were introduced to this if statement, risking that a
queue with non-zero id can reenable the disabled interface.

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index aa2093325be1..4734472aa620 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -2025,9 +2025,15 @@ int xenvif_kthread_guest_rx(void *data)
                  * context so we defer it here, if this thread is
                  * associated with queue 0.
                  */
-                if (unlikely(queue->vif->disabled && queue->id == 0))
+                if (unlikely(queue->vif->disabled && queue->id == 0)) {
                         xenvif_carrier_off(queue->vif);
-                else if (unlikely(test_and_clear_bit(QUEUE_STATUS_RX_PURGE_EVENT,
+                } else if (unlikely(queue->vif->disabled)) {
+                        /* kthread_stop() would be called upon this thread soon,
+                         * be a bit proactive
+                         */
+                        skb_queue_purge(&queue->rx_queue);
+                        queue->rx_last_skb_slots = 0;
+                } else if (unlikely(test_and_clear_bit(QUEUE_STATUS_RX_PURGE_EVENT,
                                                      &queue->status))) {
                         xenvif_rx_purge_event(queue);
                 } else if (!netif_carrier_ok(queue->vif->dev)) {