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

stable inclusion
from stable-v5.10.159
commit 83632fc41449c480f2d0193683ec202caaa186c9
category: bugfix
bugzilla: 188137, https://gitee.com/src-openeuler/kernel/issues/I651DP
CVE: CVE-2022-42328

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=83632fc41449c480f2d0193683ec202caaa186c9

--------------------------------

[ Upstream commit 74e7e1ef ]

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: be81992f ("xen/netback: don't queue unlimited number of packages")
Reported-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

conflict:
	drivers/net/xen-netback/common.h
Signed-off-by: NLu Wei <luwei32@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/xen-netback/common.h

@@ -395,7 +395,7 @@ 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_action(struct xenvif_queue *queue);
-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);
 

drivers/net/xen-netback/interface.c

@@ -269,14 +269,16 @@ 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;
 }
 

drivers/net/xen-netback/rx.c

@@ -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)