# CVE-2025-39920: pcmcia: Add error handling for add_interval() in do_validate_mem()

> A missing error check in the Linux kernel PCMCIA driver can cause a null pointer dereference, leading to a system crash.

- **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 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-68046, BELL-CVE-2025-39920, DEBIAN-CVE-2025-39920, GHSA-3gqp-rpmv-vmwg, ROOT-OS-DEBIAN-11-CVE-2025-39920, ROOT-OS-UBUNTU-2204-CVE-2025-39920, ROOT-OS-UBUNTU-2404-CVE-2025-39920, UBUNTU-CVE-2025-39920

## What is CVE-2025-39920?

CVE-2025-39920 is a medium-severity vulnerability in Debian Debian Linux, 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:

pcmcia: Add error handling for add_interval() in do_validate_mem()

In the do_validate_mem(), the call to add_interval() does not
handle errors. If kmalloc() fails in add_interval(), it could
result in a null pointer being inserted into the linked list,
leading to illegal memory access when sub_interval() is called
next.

This patch adds an error handling for the add_interval(). If
add_interval() returns an error, the function will return early
with the error code.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-39920?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-39920?

Apply the vendor's patch.

## Is CVE-2025-39920 being exploited?

There is no known exploitation of CVE-2025-39920 in the wild and no public exploit code.

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- [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-2025-39920 and fix it if it is affected.

What it is: CVE-2025-39920 is a medium-severity vulnerability in Debian Debian Linux, 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-2025-39920 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-2025-39920/ (Markdown: https://insights.sbomify.com/CVE-2025-39920/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39920
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39920
- OSV: https://osv.dev/vulnerability/CVE-2025-39920

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39920/
Summaries are generated and may contain mistakes; the official description above is the record.