# CVE-2024-27038: clk: Fix clk_core_get NULL dereference

> A NULL pointer dereference in the Linux kernel clock subsystem can cause a system crash, requiring a kernel patch to fix.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 May 2024
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-40337, BELL-CVE-2024-27038, DEBIAN-CVE-2024-27038, GHSA-6f8x-5hmv-67rj, UBUNTU-CVE-2024-27038

## What is CVE-2024-27038?

CVE-2024-27038 is a medium-severity vulnerability in Debian Debian Linux, published on 1 May 2024. 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:

clk: Fix clk_core_get NULL dereference

It is possible for clk_core_get to dereference a NULL in the following
sequence:

clk_core_get()
    of_clk_get_hw_from_clkspec()
        __of_clk_get_hw_from_provider()
            __clk_get_hw()

__clk_get_hw() can return NULL which is dereferenced by clk_core_get() at
hw->core.

Prior to commit dde4eff47c82 ("clk: Look for parents with clkdev based
clk_lookups") the check IS_ERR_OR_NULL() was performed which would have
caught the NULL.

Reading the description of this function it talks about returning NULL but
that cannot be so at the moment.

Update the function to check for hw before dereferencing it and return NULL
if hw is NULL.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-27038?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2024-27038?

Apply the vendor's patch.

## Is CVE-2024-27038 being exploited?

There is no known exploitation of CVE-2024-27038 in the wild and no public exploit code.

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## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-27038 and fix it if it is affected.

What it is: CVE-2024-27038 is a medium-severity vulnerability in Debian Debian Linux, published on 1 May 2024. 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-2024-27038 in the wild and no public exploit code.

Affected product: Debian Debian 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-2024-27038/ (Markdown: https://insights.sbomify.com/CVE-2024-27038/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27038
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27038
- OSV: https://osv.dev/vulnerability/CVE-2024-27038

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-27038/
Summaries are generated and may contain mistakes; the official description above is the record.