# CVE-2026-31552: wifi: wlcore: Return -ENOMEM instead of -EAGAIN if there is not enough headroom

> A logic error in the wlcore Wi-Fi driver causes an infinite loop and CPU soft lockup when memory allocation fails, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Apr 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2026-31552, DEBIAN-CVE-2026-31552, GHSA-f5xv-cjm8-337g, ROOT-OS-DEBIAN-11-CVE-2026-31552, ROOT-OS-DEBIAN-12-CVE-2026-31552, ROOT-OS-DEBIAN-13-CVE-2026-31552, ROOT-OS-UBUNTU-2204-CVE-2026-31552, ROOT-OS-UBUNTU-2404-CVE-2026-31552, UBUNTU-CVE-2026-31552

## What is CVE-2026-31552?

CVE-2026-31552 is a high-severity denial of service vulnerability in Linux kernel, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

wifi: wlcore: Return -ENOMEM instead of -EAGAIN if there is not enough headroom

Since upstream commit e75665dd0968 ("wifi: wlcore: ensure skb headroom
before skb_push"), wl1271_tx_allocate() and with it
wl1271_prepare_tx_frame() returns -EAGAIN if pskb_expand_head() fails.
However, in wlcore_tx_work_locked(), a return value of -EAGAIN from
wl1271_prepare_tx_frame() is interpreted as the aggregation buffer being
full. This causes the code to flush the buffer, put the skb back at the
head of the queue, and immediately retry the same skb in a tight while
loop.

Because wlcore_tx_work_locked() holds wl->mutex, and the retry happens
immediately with GFP_ATOMIC, this will result in an infinite loop and a
CPU soft lockup. Return -ENOMEM instead so the packet is dropped and
the loop terminates.

The problem was found by an experimental code review agent based on
gemini-3.1-pro while reviewing backports into v6.18.y.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-31552?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31552?

Apply the vendor's patch.

## Is CVE-2026-31552 being exploited?

There is no known exploitation of CVE-2026-31552 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-2026-31552 and fix it if it is affected.

What it is: CVE-2026-31552 is a high-severity denial of service vulnerability in Linux kernel, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-31552 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-2026-31552/ (Markdown: https://insights.sbomify.com/CVE-2026-31552/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31552
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31552
- OSV: https://osv.dev/vulnerability/CVE-2026-31552

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31552/
Summaries are generated and may contain mistakes; the official description above is the record.