xen-netfront: avoid leaking resources when setup_netfront fails

We should correctly free related resources (grant ref, memory page, evtchn)
when setup_netfront fails.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Liu 2013-05-20 01:05:12 +00:00 committed by David S. Miller
parent 6dffbe53fb
commit 1ca2983aaa

View File

@ -1532,40 +1532,49 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info)
FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(txs));
if (err < 0) {
free_page((unsigned long)txs);
goto fail;
}
if (err < 0)
goto grant_tx_ring_fail;
info->tx_ring_ref = err;
rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
if (!rxs) {
err = -ENOMEM;
xenbus_dev_fatal(dev, err, "allocating rx ring page");
goto fail;
goto alloc_rx_ring_fail;
}
SHARED_RING_INIT(rxs);
FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
if (err < 0) {
free_page((unsigned long)rxs);
goto fail;
}
if (err < 0)
goto grant_rx_ring_fail;
info->rx_ring_ref = err;
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)
goto fail;
goto alloc_evtchn_fail;
err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt,
0, netdev->name, netdev);
if (err < 0)
goto fail;
goto bind_fail;
netdev->irq = err;
return 0;
fail:
/* If we fail to setup netfront, it is safe to just revoke access to
* granted pages because backend is not accessing it at this point.
*/
bind_fail:
xenbus_free_evtchn(dev, info->evtchn);
alloc_evtchn_fail:
gnttab_end_foreign_access_ref(info->rx_ring_ref, 0);
grant_rx_ring_fail:
free_page((unsigned long)rxs);
alloc_rx_ring_fail:
gnttab_end_foreign_access_ref(info->tx_ring_ref, 0);
grant_tx_ring_fail:
free_page((unsigned long)txs);
fail:
return err;
}