# CVE-2023-53484: lib: cpu_rmap: Avoid use after free on rmap->obj array entries

> A use-after-free vulnerability in the Linux kernel's cpu_rmap library could allow attackers to execute arbitrary code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-53484, DEBIAN-CVE-2023-53484, GHSA-9598-2w9x-r9v4, UBUNTU-CVE-2023-53484

## What is CVE-2023-53484?

CVE-2023-53484 is a high-severity use after free vulnerability in Linux kernel, published on 1 Oct 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:

lib: cpu_rmap: Avoid use after free on rmap->obj array entries

When calling irq_set_affinity_notifier() with NULL at the notify
argument, it will cause freeing of the glue pointer in the
corresponding array entry but will leave the pointer in the array. A
subsequent call to free_irq_cpu_rmap() will try to free this entry again
leading to possible use after free.

Fix that by setting NULL to the array entry and checking that we have
non-zero at the array entry when iterating over the array in
free_irq_cpu_rmap().

The current code does not suffer from this since there are no cases
where irq_set_affinity_notifier(irq, NULL) (note the NULL passed for the
notify arg) is called, followed by a call to free_irq_cpu_rmap() so we
don't hit and issue. Subsequent patches in this series excersize this
flow, hence the required fix.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2023-53484?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53484?

Apply the vendor's patch.

## Is CVE-2023-53484 being exploited?

There is no known exploitation of CVE-2023-53484 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53484 and fix it if it is affected.

What it is: CVE-2023-53484 is a high-severity use after free vulnerability in Linux kernel, published on 1 Oct 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-2023-53484 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2023-53484/ (Markdown: https://insights.sbomify.com/CVE-2023-53484/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53484
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53484
- OSV: https://osv.dev/vulnerability/CVE-2023-53484

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53484/
Summaries are generated and may contain mistakes; the official description above is the record.