In the Linux kernel, the following vulnerability has been resolved: xen-netback: Fix XenBus...

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