[PATCH] xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend()

[Boris Ostrovsky]

rx_refill_timer should be deleted as soon as we disconnect from the
backend since otherwise it is possible for the timer to go off before
we get to xennet_destroy_queues(). If this happens we may dereference
queue->rx.sring which is set to NULL in xennet_disconnect_backend().

Signed-off-by: Boris Ostrovsky <boris.ostrov...@oracle.com>
CC: sta...@vger.kernel.org
---
 drivers/net/xen-netfront.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 8315fe7..722fe9f 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1379,6 +1379,8 @@ static void xennet_disconnect_backend(struct 
netfront_info *info)
        for (i = 0; i < num_queues && info->queues; ++i) {
                struct netfront_queue *queue = &info->queues[i];
 
+               del_timer_sync(&queue->rx_refill_timer);
+
                if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
                        unbind_from_irqhandler(queue->tx_irq, queue);
                if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
@@ -1733,7 +1735,6 @@ static void xennet_destroy_queues(struct netfront_info 
*info)
 
                if (netif_running(info->netdev))
                        napi_disable(&queue->napi);
-               del_timer_sync(&queue->rx_refill_timer);
                netif_napi_del(&queue->napi);
        }
 
-- 
1.8.3.1