From ad0681185770716523c81b156c44b9804d7b8ed2 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Wed, 27 May 2015 15:46:10 +0100 Subject: [PATCH] xen-netfront: properly destroy queues when removing device xennet_remove() freed the queues before freeing the netdevice which results in a use-after-free when free_netdev() tries to delete the napi instances that have already been freed. Fix this by fully destroy the queues (which includes deleting the napi instances) before freeing the netdevice. Signed-off-by: David Vrabel Reviewed-by: Boris Ostrovsky Signed-off-by: David S. Miller --- drivers/net/xen-netfront.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 3f45afd4382e..e031c943286e 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1698,6 +1698,7 @@ 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); } @@ -2102,9 +2103,6 @@ static const struct attribute_group xennet_dev_group = { static int xennet_remove(struct xenbus_device *dev) { struct netfront_info *info = dev_get_drvdata(&dev->dev); - unsigned int num_queues = info->netdev->real_num_tx_queues; - struct netfront_queue *queue = NULL; - unsigned int i = 0; dev_dbg(&dev->dev, "%s\n", dev->nodename); @@ -2112,16 +2110,7 @@ static int xennet_remove(struct xenbus_device *dev) unregister_netdev(info->netdev); - for (i = 0; i < num_queues; ++i) { - queue = &info->queues[i]; - del_timer_sync(&queue->rx_refill_timer); - } - - if (num_queues) { - kfree(info->queues); - info->queues = NULL; - } - + xennet_destroy_queues(info); xennet_free_netdev(info->netdev); return 0; -- 2.20.1