4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Boris Ostrovsky <[email protected]> commit 74470954857c264168d2b5a113904cf0cfd27d18 upstream. 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 <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/net/xen-netfront.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1391,6 +1391,8 @@ static void xennet_disconnect_backend(st 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)) { @@ -1745,7 +1747,6 @@ static void xennet_destroy_queues(struct if (netif_running(info->netdev)) napi_disable(&queue->napi); - del_timer_sync(&queue->rx_refill_timer); netif_napi_del(&queue->napi); }
