# CVE-2026-46041: greybus: gb-beagleplay: fix sleep in atomic context in hdlc_tx_frames()

> A bug in the Linux kernel greybus driver causes a system crash when sleeping while holding a spinlock, leading to 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:** 27 May 2026
- **Updated:** 14 Jun 2026
- **Also known as:** BELL-CVE-2026-46041, DEBIAN-CVE-2026-46041, GHSA-f857-h46c-q655, ROOT-OS-UBUNTU-2404-CVE-2026-46041, UBUNTU-CVE-2026-46041

## What is CVE-2026-46041?

CVE-2026-46041 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 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:

greybus: gb-beagleplay: fix sleep in atomic context in hdlc_tx_frames()

hdlc_append() calls usleep_range() to wait for circular buffer space,
but it is called with tx_producer_lock (a spinlock) held via
hdlc_tx_frames() -> hdlc_append_tx_frame()/hdlc_append_tx_u8()/etc.
Sleeping while holding a spinlock is illegal and can trigger
"BUG: scheduling while atomic".

Fix this by moving the buffer-space wait out of hdlc_append() and into
hdlc_tx_frames(), before the spinlock is acquired.  The new flow:

 1. Pre-calculate the worst-case encoded frame length.
 2. Wait (with sleep) outside the lock until enough space is available,
    kicking the TX consumer work to drain the buffer.
 3. Acquire the spinlock, re-verify space, and write the entire frame
    atomically.

This ensures that sleeping only happens without any lock held, and
that frames are either fully enqueued or not written at all.

This bug is found by CodeQL static analysis tool (interprocedural
sleep-in-atomic query) and my code review.

## Which versions are affected by CVE-2026-46041?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46041?

Apply the vendor's patch.

## Is CVE-2026-46041 being exploited?

There is no known exploitation of CVE-2026-46041 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-2026-46041 and fix it if it is affected.

What it is: CVE-2026-46041 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 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-2026-46041 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-2026-46041/ (Markdown: https://insights.sbomify.com/CVE-2026-46041/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46041
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46041
- OSV: https://osv.dev/vulnerability/CVE-2026-46041

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46041/
Summaries are generated and may contain mistakes; the official description above is the record.