# CVE-2023-53989: arm64: mm: fix VA-range sanity check

> A logic error in the Linux kernel arm64 memory management sanity check could allow incorrect mapping warnings, requiring kernel-level access to exploit.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 1 Jun 2026
- **Also known as:** BELL-CVE-2023-53989, DEBIAN-CVE-2023-53989, GHSA-49xq-j8p7-h965, ROOT-OS-DEBIAN-12-CVE-2023-53989, UBUNTU-CVE-2023-53989

## What is CVE-2023-53989?

CVE-2023-53989 is a vulnerability in Linux, published on 24 Dec 2025. 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:

arm64: mm: fix VA-range sanity check

Both create_mapping_noalloc() and update_mapping_prot() sanity-check
their 'virt' parameter, but the check itself doesn't make much sense.
The condition used today appears to be a historical accident.

The sanity-check condition:

	if ((virt >= PAGE_END) && (virt < VMALLOC_START)) {
		[ ... warning here ... ]
		return;
	}

... can only be true for the KASAN shadow region or the module region,
and there's no reason to exclude these specifically for creating and
updateing mappings.

When arm64 support was first upstreamed in commit:

  c1cc1552616d0f35 ("arm64: MMU initialisation")

... the condition was:

	if (virt < VMALLOC_START) {
		[ ... warning here ... ]
		return;
	}

At the time, VMALLOC_START was the lowest kernel address, and this was
checking whether 'virt' would be translated via TTBR1.

Subsequently in commit:

  14c127c957c1c607 ("arm64: mm: Flip kernel VA space")

... the condition was changed to:

	if ((virt >= VA_START) && (virt < VMALLOC_START)) {
		[ ... warning here ... ]
		return;
	}

This appear to have been a thinko. The commit moved the linear map to
the bottom of the kernel address space, with VMALLOC_START being at the
halfway point. The old condition would warn for changes to the linear
map below this, and at the time VA_START was the end of the linear map.

Subsequently we cleaned up the naming of VA_START in commit:

  77ad4ce69321abbe ("arm64: memory: rename VA_START to PAGE_END")

... keeping the erroneous condition as:

	if ((virt >= PAGE_END) && (virt < VMALLOC_START)) {
		[ ... warning here ... ]
		return;
	}

Correct the condition to check against the start of the TTBR1 address
space, which is currently PAGE_OFFSET. This simplifies the logic, and
more clearly matches the "outside kernel range" message in the warning.

## Which versions are affected by CVE-2023-53989?


## How do I fix CVE-2023-53989?

Apply the vendor's patch.

## Is CVE-2023-53989 being exploited?

There is no known exploitation of CVE-2023-53989 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53989 and fix it if it is affected.

What it is: CVE-2023-53989 is a vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-53989 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-53989/ (Markdown: https://insights.sbomify.com/CVE-2023-53989/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53989
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53989
- OSV: https://osv.dev/vulnerability/CVE-2023-53989

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53989/
Summaries are generated and may contain mistakes; the official description above is the record.