In the Linux kernel, the following vulnerability has been resolved:
xen-netback: Fix XenBus connection failure cleanup
xenvif_get_stats and xenvif_get_ethtool_stats capture vif->num_queues
under rcu_read_lock. We need to unpublish vif->num_queues before
synchronize_net to ensure that readers that come afterwards will not
read a non-zero vif->num_queues and attempt to access invalid queues.
This is the same cleanup algorithm as used in backend_disconnect and
added in commit b17075d5c198 ("xen-netback: fix race condition on XenBus
disconnect").
This is XSA-531