An error in the Linux kernel’s virtio tiny radio clock (RTC) driver allows the kernel to attempt to reinitialize virtqueues without first deleting the old ones. This results in a null pointer dereference (CWE‑476) during restoration of the device, crashing the guest kernel. The crash provides a denial of service to the virtual machine by forcing a reboot or halt of the operating system. The weakness arises from improper management of device resources.

The vulnerable code path is part of the virtio driver that handles RTC devices. It applies to all Linux kernels that implement virtio‑RTC, which is the default on most mainstream distributions. No specific version list is provided, so any kernel before the fix carries the flaw. Linux is the sole vendor, and the issue resides within the core kernel code rather than a particular distribution or patch level.

The flaw leads only to a kernel crash; it is not a privilege escalation or remote code execution vulnerability. However, a crash can disrupt services and availability. The CVSS score of 7.8 indicates a high severity, while the EPSS score is less than 1%, indicating a very low exploitation probability. The vulnerability is not listed in CISA KEV, so current exploitation probability remains uncertain. Attackers would need to trigger a device restore, which is typically performed through the virtualization layer or a guest reboot. The lack of a publicly available exploit and the requirement of a restoration event reduce the likelihood but do not eliminate risk, making timely patching advisable.