From f9244fb55f37356f75c739c57323d9422d7aa0f8 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Thu, 7 Nov 2024 16:17:00 +0100 Subject: xen/netfront: fix crash when removing device MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When removing a netfront device directly after a suspend/resume cycle it might happen that the queues have not been setup again, causing a crash during the attempt to stop the queues another time. Fix that by checking the queues are existing before trying to stop them. This is XSA-465 / CVE-2024-53240. Reported-by: Marek Marczykowski-Górecki Fixes: d50b7914fae0 ("xen-netfront: Fix NULL sring after live migration") Signed-off-by: Juergen Gross --- drivers/net/xen-netfront.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 4265c1cd0ff7..63fe51d0e64d 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -867,7 +867,7 @@ static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev static int xennet_close(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); - unsigned int num_queues = dev->real_num_tx_queues; + unsigned int num_queues = np->queues ? dev->real_num_tx_queues : 0; unsigned int i; struct netfront_queue *queue; netif_tx_stop_all_queues(np->netdev); @@ -882,6 +882,9 @@ static void xennet_destroy_queues(struct netfront_info *info) { unsigned int i; + if (!info->queues) + return; + for (i = 0; i < info->netdev->real_num_tx_queues; i++) { struct netfront_queue *queue = &info->queues[i]; -- 2.43.0