xen/netback: don't call kfree_skb() with interrupts disabled

It is not allowed to call kfree_skb() from hardware interrupt
context or with interrupts being disabled. So remove kfree_skb()
from the spin_lock_irqsave() section and use the already existing
"drop" label in xenvif_start_xmit() for dropping the SKB. At the
same time replace the dev_kfree_skb() call there with a call of
dev_kfree_skb_any(), as xenvif_start_xmit() can be called with
disabled interrupts.

This is XSA-424 / CVE-2022-42328 / CVE-2022-42329.

Fixes: be81992f90 ("xen/netback: don't queue unlimited number of packages")
Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Juergen Gross
2022-12-06 08:54:24 +01:00
parent ad7f402ae4
commit 74e7e1efda
3 changed files with 10 additions and 6 deletions

View File

@@ -254,14 +254,16 @@ xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
skb_clear_hash(skb);
xenvif_rx_queue_tail(queue, skb);
if (!xenvif_rx_queue_tail(queue, skb))
goto drop;
xenvif_kick_thread(queue);
return NETDEV_TX_OK;
drop:
vif->dev->stats.tx_dropped++;
dev_kfree_skb(skb);
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}