# CVE-2025-68336: locking/spinlock/debug: Fix data-race in do_raw_write_lock

> A data race in the Linux kernel's spinlock debug code can lead to inconsistent state, potentially causing system instability or crashes.

- **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:** 22 Dec 2025
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-72889, BELL-CVE-2025-68336, DEBIAN-CVE-2025-68336, GHSA-hrvw-g8xf-vhvj, ROOT-OS-DEBIAN-11-CVE-2025-68336, ROOT-OS-DEBIAN-12-CVE-2025-68336, ROOT-OS-UBUNTU-2204-CVE-2025-68336, ROOT-OS-UBUNTU-2404-CVE-2025-68336, UBUNTU-CVE-2025-68336

## What is CVE-2025-68336?

CVE-2025-68336 is a high-severity vulnerability in Linux, published on 22 Dec 2025. 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:

locking/spinlock/debug: Fix data-race in do_raw_write_lock

KCSAN reports:

BUG: KCSAN: data-race in do_raw_write_lock / do_raw_write_lock

write (marked) to 0xffff800009cf504c of 4 bytes by task 1102 on cpu 1:
 do_raw_write_lock+0x120/0x204
 _raw_write_lock_irq
 do_exit
 call_usermodehelper_exec_async
 ret_from_fork

read to 0xffff800009cf504c of 4 bytes by task 1103 on cpu 0:
 do_raw_write_lock+0x88/0x204
 _raw_write_lock_irq
 do_exit
 call_usermodehelper_exec_async
 ret_from_fork

value changed: 0xffffffff -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1103 Comm: kworker/u4:1 6.1.111

Commit 1a365e822372 ("locking/spinlock/debug: Fix various data races") has
adressed most of these races, but seems to be not consistent/not complete.

>From do_raw_write_lock() only debug_write_lock_after() part has been
converted to WRITE_ONCE(), but not debug_write_lock_before() part.
Do it now.

## Which versions are affected by CVE-2025-68336?


## How do I fix CVE-2025-68336?

Apply the vendor's patch.

## Is CVE-2025-68336 being exploited?

There is no known exploitation of CVE-2025-68336 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68336 and fix it if it is affected.

What it is: CVE-2025-68336 is a high-severity vulnerability in Linux, published on 22 Dec 2025. 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-2025-68336 in the wild and no public exploit code.

Affected product: Linux. 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-2025-68336/ (Markdown: https://insights.sbomify.com/CVE-2025-68336/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68336
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68336
- OSV: https://osv.dev/vulnerability/CVE-2025-68336

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68336/
Summaries are generated and may contain mistakes; the official description above is the record.