# CVE-2025-38388: firmware: arm_ffa: Replace mutex with rwlock to avoid sleep in atomic context

> A race condition in the Linux kernel ARM FFA firmware driver causes kernel warnings and potential instability by sleeping in atomic context.

- **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:** 25 Jul 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-38388, DEBIAN-CVE-2025-38388, GHSA-58vg-w4wx-wp6p, ROOT-OS-UBUNTU-2404-CVE-2025-38388, UBUNTU-CVE-2025-38388

## What is CVE-2025-38388?

CVE-2025-38388 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 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:

firmware: arm_ffa: Replace mutex with rwlock to avoid sleep in atomic context

The current use of a mutex to protect the notifier hashtable accesses
can lead to issues in the atomic context. It results in the below
kernel warnings:

  |  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258
  |  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0
  |  preempt_count: 1, expected: 0
  |  RCU nest depth: 0, expected: 0
  |  CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0 #4
  |  Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn
  |  Call trace:
  |   show_stack+0x18/0x24 (C)
  |   dump_stack_lvl+0x78/0x90
  |   dump_stack+0x18/0x24
  |   __might_resched+0x114/0x170
  |   __might_sleep+0x48/0x98
  |   mutex_lock+0x24/0x80
  |   handle_notif_callbacks+0x54/0xe0
  |   notif_get_and_handle+0x40/0x88
  |   generic_exec_single+0x80/0xc0
  |   smp_call_function_single+0xfc/0x1a0
  |   notif_pcpu_irq_work_fn+0x2c/0x38
  |   process_one_work+0x14c/0x2b4
  |   worker_thread+0x2e4/0x3e0
  |   kthread+0x13c/0x210
  |   ret_from_fork+0x10/0x20

To address this, replace the mutex with an rwlock to protect the notifier
hashtable accesses. This ensures that read-side locking does not sleep and
multiple readers can acquire the lock concurrently, avoiding unnecessary
contention and potential deadlocks. Writer access remains exclusive,
preserving correctness.

This change resolves warnings from lockdep about potential sleep in
atomic context.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2025-38388?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38388?

Apply the vendor's patch.

## Is CVE-2025-38388 being exploited?

There is no known exploitation of CVE-2025-38388 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-2025-38388 and fix it if it is affected.

What it is: CVE-2025-38388 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 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-2025-38388 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-2025-38388/ (Markdown: https://insights.sbomify.com/CVE-2025-38388/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38388
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38388
- OSV: https://osv.dev/vulnerability/CVE-2025-38388

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38388/
Summaries are generated and may contain mistakes; the official description above is the record.