# CVE-2024-36961: thermal/debugfs: Fix two locking issues with thermal zone debug

> A race condition in the Linux kernel thermal debugfs code allows a local attacker to trigger a NULL pointer dereference, causing a system crash.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 3 Jun 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-36961, DEBIAN-CVE-2024-36961, GHSA-rcqf-hc64-m737, UBUNTU-CVE-2024-36961

## What is CVE-2024-36961?

CVE-2024-36961 is a high-severity vulnerability in Linux kernel, published on 3 Jun 2024. 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:

thermal/debugfs: Fix two locking issues with thermal zone debug

With the current thermal zone locking arrangement in the debugfs code,
user space can open the "mitigations" file for a thermal zone before
the zone's debugfs pointer is set which will result in a NULL pointer
dereference in tze_seq_start().

Moreover, thermal_debug_tz_remove() is not called under the thermal
zone lock, so it can run in parallel with the other functions accessing
the thermal zone's struct thermal_debugfs object.  Then, it may clear
tz->debugfs after one of those functions has checked it and the
struct thermal_debugfs object may be freed prematurely.

To address the first problem, pass a pointer to the thermal zone's
struct thermal_debugfs object to debugfs_create_file() in
thermal_debug_tz_add() and make tze_seq_start(), tze_seq_next(),
tze_seq_stop(), and tze_seq_show() retrieve it from s->private
instead of a pointer to the thermal zone object.  This will ensure
that tz_debugfs will be valid across the "mitigations" file accesses
until thermal_debugfs_remove_id() called by thermal_debug_tz_remove()
removes that file.

To address the second problem, use tz->lock in thermal_debug_tz_remove()
around the tz->debugfs value check (in case the same thermal zone is
removed at the same time in two different threads) and its reset to NULL.

Cc :6.8+ <stable@vger.kernel.org> # 6.8+

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-36961?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-36961?

Apply the vendor's patch.

## Is CVE-2024-36961 being exploited?

There is no known exploitation of CVE-2024-36961 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-2024-36961 and fix it if it is affected.

What it is: CVE-2024-36961 is a high-severity vulnerability in Linux kernel, published on 3 Jun 2024. 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-2024-36961 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-2024-36961/ (Markdown: https://insights.sbomify.com/CVE-2024-36961/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36961
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36961
- OSV: https://osv.dev/vulnerability/CVE-2024-36961

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36961/
Summaries are generated and may contain mistakes; the official description above is the record.