# CVE-2020-29534: Race condition in n/a

> A race condition in the Linux kernel io_uring subsystem allows local attackers to escalate privileges or execute code via improper file structure reference handling.

- **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:** 3 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-29534, GHSA-6pj8-q9pf-wvp7, UBUNTU-CVE-2020-29534

## What is CVE-2020-29534?

CVE-2020-29534 is a high-severity vulnerability in Linux kernel, published on 3 Dec 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in the Linux kernel before 5.9.3. io_uring takes a non-refcounted reference to the files_struct of the process that submitted a request, causing execve() to incorrectly optimize unshare_fd(), aka CID-0f2122045b94.

## Which versions are affected by CVE-2020-29534?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2020-29534?

Apply the vendor's patch.

## Is CVE-2020-29534 being exploited?

There is no known exploitation of CVE-2020-29534 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-2020-29534 and fix it if it is affected.

What it is: CVE-2020-29534 is a high-severity vulnerability in Linux kernel, published on 3 Dec 2020. 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-2020-29534 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-2020-29534/ (Markdown: https://insights.sbomify.com/CVE-2020-29534/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-29534
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-29534
- OSV: https://osv.dev/vulnerability/CVE-2020-29534

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-29534/
Summaries are generated and may contain mistakes; the official description above is the record.