CVE-2026-74311 virtio: rtc: tear down old virtqueues before restore
A null pointer dereference in the Linux kernel virtio RTC driver during device restore can crash the guest kernel, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74311?
CVE-2026-74311 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
virtio: rtc: tear down old virtqueues before restore
virtio_device_restore() resets the device and restores the negotiated features before calling ->restore(). viortc_freeze() intentionally leaves the existing virtqueues in place so the alarm queue can still wake the system, but viortc_restore() immediately calls viortc_init_vqs() without first deleting those old queues.
If virtqueue reinitialization fails on virtio-pci, the transport error path can run vp_del_vqs() against a newly allocated vp_dev->vqs array while vdev->vqs still contains the old virtqueues. vp_del_vqs() then looks up queue state through the new array and can dereference a NULL info pointer in vp_del_vq(), crashing the guest kernel during restore.
This can also happen during a non-faulty reinitialization, when one of the vp_find_vqs_msix() attempts is unsuccessful before a later attempt would succeed.
Delete the stale virtqueues before rebuilding them. If restore fails before virtio_device_ready(), reuse the remove path to stop the device. Once the device is ready, return errors directly instead of deleting the virtqueues again.
Which versions are affected by CVE-2026-74311?
How do I fix CVE-2026-74311?
Apply the vendor's patch.
Is CVE-2026-74311 being exploited?
There is no known exploitation of CVE-2026-74311 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74311, DEBIAN-CVE-2026-74311, GHSA-4fvg-c4gx-gxg2, UBUNTU-CVE-2026-74311.