xen/netback: don't call kfree_skb() with interrupts disabled
[ Upstream commit 74e7e1efdad45580cc3839f2a155174cf158f9b5 ]
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.
BUG=b/262368890,b/262369401
TEST=presubmit,validation
RELEASE_NOTE=Fixed CVE-2022-42328,CVE-2022-42329 in the Linux kernel.
cos-patch: security-moderate
Fixes: be81992f9086 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Change-Id: I42ee54d4445655afa3d43589f37874960514bba7
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/40288
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index f7e746f..4b8b684 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -392,7 +392,7 @@
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);
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 8090895..c302862 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -269,14 +269,16 @@
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;
}
diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
index 85a5a62..7c6de61 100644
--- a/drivers/net/xen-netback/rx.c
+++ b/drivers/net/xen-netback/rx.c
@@ -82,9 +82,10 @@
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 @@
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 @@
}
spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
+
+ return ret;
}
static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
