CVE-2021-46953: ACPI: GTDT: Don't corrupt interrupt mappings on watchdow probe failure

Severity: medium (CVSS 6.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-27 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: ACPI: GTDT: Don't corrupt interrupt mappings on watchdow probe failure When failing the driver probe because of invalid firmware properties, the GTDT driver unmaps the interrupt that it mapped earlier. However, it never checks whether the mapping of the interrupt actially succeeded. Even more, should the firmware report an illegal interrupt number that overlaps with the GIC SGI range, this can result in an IPI being unmapped, and subsequent fireworks (as reported by Dann Frazier). Rework the driver to have a slightly saner behaviour and actually check whether the interrupt has been mapped before unmapping things.

Affected products

Linux kernel: from 4.12.0 before 4.14.233; from 4.15.0 before 4.19.191; from 4.20.0 before 5.4.118; from 5.5.0 before 5.10.36; from 5.11.0 before 5.11.20; from 5.12.0 before 5.12.3 — fixed in 4.14.233, 4.19.191, 5.10.36, 5.11.20, 5.12.3, 5.4.118

How to fix

Upgrade to a fixed version: Linux kernel 4.14.233, 4.19.191, 5.10.36, 5.11.20. Check the vendor advisory for mitigations.

References

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