# CVE-2023-6915: Kernel: null pointer dereference vulnerability in ida_free in lib/idr.c

> An attacker can cause a denial of service in the Linux Kernel via a null pointer dereference in ida_free due to a missing check.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jan 2024
- **Updated:** 6 Nov 2025
- **Also known as:** AZL-33550, AZL-34868, BELL-CVE-2023-6915, DEBIAN-CVE-2023-6915, GHSA-3cfm-49vw-5qrv, OESA-2024-1145, UBUNTU-CVE-2023-6915, USN-6650-1

## What is CVE-2023-6915?

CVE-2023-6915 is a medium-severity vulnerability in Debian Debian Linux, published on 15 Jan 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A Null pointer dereference problem was found in ida_free in lib/idr.c in the Linux Kernel. This issue may allow an attacker using this library to cause a denial of service problem due to a missing check at a function return.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-6915?

It affects 24 products.


Products: Debian Debian Linux, Linux kernel, Redhat Codeready Linux Builder, Redhat Codeready Linux Builder for Arm64, Redhat Codeready Linux Builder for Eus, Redhat Codeready Linux Builder for Ibm Z Systems, Redhat Codeready Linux Builder for Ibm Z Systems Eus, Redhat Codeready Linux Builder for Power Little Endian, Redhat Codeready Linux Builder for Power Little Endian Els, Redhat Codeready Linux Builder for Power Little Endian Eus, Redhat Enterprise Linux, Redhat Enterprise Linux Eus, Redhat Enterprise Linux for Els, Redhat Enterprise Linux for Ibm Z Systems, Redhat Enterprise Linux for Ibm Z Systems Els, Redhat Enterprise Linux for Ibm Z Systems Eus, Redhat Enterprise Linux for Power Little Endian, Redhat Enterprise Linux for Power Little Endian Els, Redhat Enterprise Linux for Power Little Endian Eus, Redhat Enterprise Linux for Real Time and 4 more.

## How do I fix CVE-2023-6915?

Apply the vendor's patch.

## Is CVE-2023-6915 being exploited?

There is no known exploitation of CVE-2023-6915 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-6915 and fix it if it is affected.

What it is: CVE-2023-6915 is a medium-severity vulnerability in Debian Debian Linux, published on 15 Jan 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-2023-6915 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-2023-6915/ (Markdown: https://insights.sbomify.com/CVE-2023-6915/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-6915
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-6915
- OSV: https://osv.dev/vulnerability/CVE-2023-6915

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-6915/
Summaries are generated and may contain mistakes; the official description above is the record.