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

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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/net/xen-netback/common.h
View File

@ -386,7 +386,7 @@ int xenvif_dealloc_kthread(void *data);
irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data);
bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread);
void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
bool xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
void xenvif_carrier_on(struct xenvif *vif);

6
drivers/net/xen-netback/interface.c
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;
}

8
drivers/net/xen-netback/rx.c
View File

@ -82,9 +82,10 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
return false;
}
void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
bool xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
{
unsigned long flags;
bool ret = true;
spin_lock_irqsave(&queue->rx_queue.lock, flags);
@ -92,8 +93,7 @@ void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
struct net_device *dev = queue->vif->dev;
netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
kfree_skb(skb);
queue->vif->dev->stats.rx_dropped++;
ret = false;
} else {
if (skb_queue_empty(&queue->rx_queue))
xenvif_update_needed_slots(queue, skb);
@ -104,6 +104,8 @@ void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
}
spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
return ret;
}
static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)