# GSD-2021-1001526: bpf: Fix integer overflow in prealloc_elems_and_freelist()

> An integer overflow in the Linux kernel BPF subsystem allows local attackers to potentially escalate privileges or execute code.

- **Severity:** Not scored
- **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:** No
- **Published:** 19 Oct 2021

## What is GSD-2021-1001526?

GSD-2021-1001526 is a vulnerability in Kernel, published on 19 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

bpf: Fix integer overflow in prealloc_elems_and_freelist()

This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven.
This ID is fixed in Linux Kernel version v4.14.251 by commit f34bcd10c4832d491049905d25ea3f46a410c426, it was introduced in version v4.6 by commit 557c0c6e7df8e14a46bd7560d193fa5bbc00a858. For more details please see the references link.

## Which versions are affected by GSD-2021-1001526?

1 open source package ship an affected version, including Kernel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Kernel` | Linux | All versions | None |

## How do I fix GSD-2021-1001526?

No fix has been published for GSD-2021-1001526 yet. Limit exposure of the affected software until one is available.

## Is GSD-2021-1001526 being exploited?

There is no known exploitation of GSD-2021-1001526 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GSD-2021-1001526 and fix it if it is affected.

What it is: GSD-2021-1001526 is a vulnerability in Kernel, published on 19 Oct 2021. 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 GSD-2021-1001526 in the wild and no public exploit code.

Affected packages and fixed versions:
- Kernel (Linux): affected all versions; no fix listed

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/GSD-2021-1001526/ (Markdown: https://insights.sbomify.com/GSD-2021-1001526/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GSD-2021-1001526

---
From sbomify Insights: https://insights.sbomify.com/GSD-2021-1001526/
Summaries are generated and may contain mistakes; the official description above is the record.