CVE-2026-74311: virtio: rtc: tear down old virtqueues before restore
In the Linux kernel, the following vulnerability has been resolved:
virtio: rtc: tear down old virtqueues before restore
virtiodevicerestore() resets the device and restores the negotiated features before calling ->restore(). viortcfreeze() intentionally leaves the existing virtqueues in place so the alarm queue can still wake the system, but viortcrestore() immediately calls viortcinitvqs() without first deleting those old queues.
If virtqueue reinitialization fails on virtio-pci, the transport error path can run vpdelvqs() against a newly allocated vpdev->vqs array while vdev->vqs still contains the old virtqueues. vpdelvqs() then looks up queue state through the new array and can dereference a NULL info pointer in vpdelvq(), crashing the guest kernel during restore.
This can also happen during a non-faulty reinitialization, when one of the vpfindvqsmsix() attempts is unsuccessful before a later attempt would succeed.
Delete the stale virtqueues before rebuilding them. If restore fails before virtiodeviceready(), reuse the remove path to stop the device. Once the device is ready, return errors directly instead of deleting the virtqueues again.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2022.23 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Operational
In virtio RTC restore and reinitialization, tear down stale virtqueues before rebuilding them. If restore or virtqueue initialization 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.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-74311?
The severity of CVE-2026-74311 is rated as 38.
How do I fix CVE-2026-74311?
To fix CVE-2026-74311, ensure that you update your Linux kernel to the latest patched version.
What systems are affected by CVE-2026-74311?
CVE-2026-74311 affects the Linux kernel with specific regard to the virtio RTC implementation.
What type of vulnerability is CVE-2026-74311?
CVE-2026-74311 is a vulnerability related to improper handling of virtqueues during the restoration process in the Linux kernel.
When was CVE-2026-74311 published?
CVE-2026-74311 was published on August 15, 2026.