# CVE-2026-31576: media: hackrf: fix to not free memory after the device is registered in hackrf_probe()

> A race condition in the Linux kernel HackRF driver allows use-after-free and double-free vulnerabilities, potentially enabling local privilege escalation or code execution.

- **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:** 24 Apr 2026
- **Updated:** 14 Jun 2026
- **Also known as:** BELL-CVE-2026-31576, DEBIAN-CVE-2026-31576, GHSA-9h3v-wrpm-q7m5, ROOT-OS-DEBIAN-11-CVE-2026-31576, ROOT-OS-DEBIAN-12-CVE-2026-31576, ROOT-OS-UBUNTU-2204-CVE-2026-31576, ROOT-OS-UBUNTU-2404-CVE-2026-31576, UBUNTU-CVE-2026-31576

## What is CVE-2026-31576?

CVE-2026-31576 is a high-severity use after free vulnerability in Linux kernel, published on 24 Apr 2026. 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:

media: hackrf: fix to not free memory after the device is registered in hackrf_probe()

In hackrf driver, the following race condition occurs:
```
		CPU0						CPU1
hackrf_probe()
  kzalloc(); // alloc hackrf_dev
  ....
  v4l2_device_register();
  ....
						fd = sys_open("/path/to/dev"); // open hackrf fd
						....
  v4l2_device_unregister();
  ....
  kfree(); // free hackrf_dev
  ....
						sys_ioctl(fd, ...);
						  v4l2_ioctl();
						    video_is_registered() // UAF!!
						....
						sys_close(fd);
						  v4l2_release() // UAF!!
						    hackrf_video_release()
						      kfree(); // DFB!!
```

When a V4L2 or video device is unregistered, the device node is removed so
new open() calls are blocked.

However, file descriptors that are already open-and any in-flight I/O-do
not terminate immediately; they remain valid until the last reference is
dropped and the driver's release() is invoked.

Therefore, freeing device memory on the error path after hackrf_probe()
has registered dev it will lead to a race to use-after-free vuln, since
those already-open handles haven't been released yet.

And since release() free memory too, race to use-after-free and
double-free vuln occur.

To prevent this, if device is registered from probe(), it should be
modified to free memory only through release() rather than calling
kfree() directly.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-31576?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31576?

Apply the vendor's patch.

## Is CVE-2026-31576 being exploited?

There is no known exploitation of CVE-2026-31576 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-2026-31576 and fix it if it is affected.

What it is: CVE-2026-31576 is a high-severity use after free vulnerability in Linux kernel, published on 24 Apr 2026. 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-2026-31576 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-2026-31576/ (Markdown: https://insights.sbomify.com/CVE-2026-31576/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31576
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31576
- OSV: https://osv.dev/vulnerability/CVE-2026-31576

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31576/
Summaries are generated and may contain mistakes; the official description above is the record.