# CVE-2026-31658: net: altera-tse: fix skb leak on DMA mapping error in tse_start_xmit()

> A memory leak in the Altera TSE network driver allows attackers to cause denial of service by triggering DMA mapping failures.

- **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 Apr 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-83891, BELL-CVE-2026-31658, DEBIAN-CVE-2026-31658, GHSA-fm9r-m74h-jfjj, ROOT-OS-DEBIAN-11-CVE-2026-31658, ROOT-OS-DEBIAN-12-CVE-2026-31658, ROOT-OS-UBUNTU-2204-CVE-2026-31658, ROOT-OS-UBUNTU-2404-CVE-2026-31658, UBUNTU-CVE-2026-31658

## What is CVE-2026-31658?

CVE-2026-31658 is a medium-severity denial of service 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:

net: altera-tse: fix skb leak on DMA mapping error in tse_start_xmit()

When dma_map_single() fails in tse_start_xmit(), the function returns
NETDEV_TX_OK without freeing the skb. Since NETDEV_TX_OK tells the
stack the packet was consumed, the skb is never freed, leaking memory
on every DMA mapping failure.

Add dev_kfree_skb_any() before returning to properly free the skb.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-31658?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31658?

Apply the vendor's patch.

## Is CVE-2026-31658 being exploited?

There is no known exploitation of CVE-2026-31658 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-2026-31658 and fix it if it is affected.

What it is: CVE-2026-31658 is a medium-severity denial of service 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-2026-31658 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-2026-31658/ (Markdown: https://insights.sbomify.com/CVE-2026-31658/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31658
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31658
- OSV: https://osv.dev/vulnerability/CVE-2026-31658

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31658/
Summaries are generated and may contain mistakes; the official description above is the record.