# CVE-2025-68725: bpf: Do not let BPF test infra emit invalid GSO types to stack

> A flaw in the Linux kernel BPF test infrastructure allows triggering invalid GSO types, potentially causing warnings or denial of service.

- **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:** 24 Dec 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-73117, AZL-78413, BELL-CVE-2025-68725, DEBIAN-CVE-2025-68725, GHSA-696c-x544-xmc9, ROOT-OS-UBUNTU-2204-CVE-2025-68725, ROOT-OS-UBUNTU-2404-CVE-2025-68725, UBUNTU-CVE-2025-68725

## What is CVE-2025-68725?

CVE-2025-68725 is a medium-severity vulnerability in Linux kernel, published on 24 Dec 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:

bpf: Do not let BPF test infra emit invalid GSO types to stack

Yinhao et al. reported that their fuzzer tool was able to trigger a
skb_warn_bad_offload() from netif_skb_features() -> gso_features_check().
When a BPF program - triggered via BPF test infra - pushes the packet
to the loopback device via bpf_clone_redirect() then mentioned offload
warning can be seen. GSO-related features are then rightfully disabled.

We get into this situation due to convert___skb_to_skb() setting
gso_segs and gso_size but not gso_type. Technically, it makes sense
that this warning triggers since the GSO properties are malformed due
to the gso_type. Potentially, the gso_type could be marked non-trustworthy
through setting it at least to SKB_GSO_DODGY without any other specific
assumptions, but that also feels wrong given we should not go further
into the GSO engine in the first place.

The checks were added in 121d57af308d ("gso: validate gso_type in GSO
handlers") because there were malicious (syzbot) senders that combine
a protocol with a non-matching gso_type. If we would want to drop such
packets, gso_features_check() currently only returns feature flags via
netif_skb_features(), so one location for potentially dropping such skbs
could be validate_xmit_unreadable_skb(), but then otoh it would be
an additional check in the fast-path for a very corner case. Given
bpf_clone_redirect() is the only place where BPF test infra could emit
such packets, lets reject them right there.

## Which versions are affected by CVE-2025-68725?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-68725?

Apply the vendor's patch.

## Is CVE-2025-68725 being exploited?

There is no known exploitation of CVE-2025-68725 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-2025-68725 and fix it if it is affected.

What it is: CVE-2025-68725 is a medium-severity vulnerability in Linux kernel, published on 24 Dec 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-2025-68725 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-2025-68725/ (Markdown: https://insights.sbomify.com/CVE-2025-68725/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68725
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68725
- OSV: https://osv.dev/vulnerability/CVE-2025-68725

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68725/
Summaries are generated and may contain mistakes; the official description above is the record.