# CVE-2024-35887: ax25: fix use-after-free bugs caused by ax25_ds_del_timer

> A use-after-free vulnerability in the Linux kernel AX.25 subsystem allows attackers to execute arbitrary code or escalate privileges during device detachment.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 19 May 2024
- **Updated:** 14 Sep 2026
- **Also known as:** AZL-54730, BELL-CVE-2024-35887, DEBIAN-CVE-2024-35887, GHSA-x3w9-8c2f-ccvj, ROOT-OS-DEBIAN-11-CVE-2024-35887, ROOT-OS-DEBIAN-12-CVE-2024-35887, UBUNTU-CVE-2024-35887

## What is CVE-2024-35887?

CVE-2024-35887 is a high-severity use after free vulnerability in Linux kernel, published on 19 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:

ax25: fix use-after-free bugs caused by ax25_ds_del_timer

When the ax25 device is detaching, the ax25_dev_device_down()
calls ax25_ds_del_timer() to cleanup the slave_timer. When
the timer handler is running, the ax25_ds_del_timer() that
calls del_timer() in it will return directly. As a result,
the use-after-free bugs could happen, one of the scenarios
is shown below:

      (Thread 1)          |      (Thread 2)
                          | ax25_ds_timeout()
ax25_dev_device_down()    |
  ax25_ds_del_timer()     |
    del_timer()           |
  ax25_dev_put() //FREE   |
                          |  ax25_dev-> //USE

In order to mitigate bugs, when the device is detaching, use
timer_shutdown_sync() to stop the timer.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-35887?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-35887?

Apply the vendor's patch.

## Is CVE-2024-35887 being exploited?

There is no known exploitation of CVE-2024-35887 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-2024-35887 and fix it if it is affected.

What it is: CVE-2024-35887 is a high-severity use after free vulnerability in Linux kernel, published on 19 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-2024-35887 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-2024-35887/ (Markdown: https://insights.sbomify.com/CVE-2024-35887/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-35887
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-35887
- OSV: https://osv.dev/vulnerability/CVE-2024-35887

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-35887/
Summaries are generated and may contain mistakes; the official description above is the record.