UBUNTU-CVE-2026-100080: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: xen-netback: Fix UAF when reading statistics data The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state. In case the data is being read via sysfs in this phase, access to already freed memory or memory being in new use is possible. Fix that by calling synchronizenet() before freeing the queue data. This is XSA-526 / CVE-2026-100080
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
In xen-netback, call synchronize_net() before freeing queue data when tearing down queues, ensuring RCU-protected statistics data is no longer accessible before it is freed. Addresses XSA-526 / CVE-2026-100080.