CVE-2021-47111

HighCVSS 7.8/10Last modified Aug 4, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

xen-netback: take a reference to the RX task thread

Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4.

Reintroduce the reference taking and add a comment this time explaining why it's needed.

This is XSA-374 / CVE-2021-28691.

Metrics

CVSS 3.1 7.8/10CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-416

Affected software

No affected versions have been published.

Timeline

Published
Mar 15, 2024
Last modified
Aug 4, 2026
NVD status
Modified

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CVE-2021-47111: High severity, CVSS 7.8 | Vulnix