# CVE-2024-49985: i2c: stm32f7: Do not prepare/unprepare clock during runtime suspend/resume

> A deadlock in the STM32F7 I2C driver can cause a denial of service when specific clock controllers are attached to the bus.

- **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:** 21 Oct 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-51774, BELL-CVE-2024-49985, DEBIAN-CVE-2024-49985, GHSA-qfhj-q535-jf9w, UBUNTU-CVE-2024-49985

## What is CVE-2024-49985?

CVE-2024-49985 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 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:

i2c: stm32f7: Do not prepare/unprepare clock during runtime suspend/resume

In case there is any sort of clock controller attached to this I2C bus
controller, for example Versaclock or even an AIC32x4 I2C codec, then
an I2C transfer triggered from the clock controller clk_ops .prepare
callback may trigger a deadlock on drivers/clk/clk.c prepare_lock mutex.

This is because the clock controller first grabs the prepare_lock mutex
and then performs the prepare operation, including its I2C access. The
I2C access resumes this I2C bus controller via .runtime_resume callback,
which calls clk_prepare_enable(), which attempts to grab the prepare_lock
mutex again and deadlocks.

Since the clock are already prepared since probe() and unprepared in
remove(), use simple clk_enable()/clk_disable() calls to enable and
disable the clock on runtime suspend and resume, to avoid hitting the
prepare_lock mutex.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-49985?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-49985?

Apply the vendor's patch.

## Is CVE-2024-49985 being exploited?

There is no known exploitation of CVE-2024-49985 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-2024-49985 and fix it if it is affected.

What it is: CVE-2024-49985 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 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-2024-49985 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-2024-49985/ (Markdown: https://insights.sbomify.com/CVE-2024-49985/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-49985
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-49985
- OSV: https://osv.dev/vulnerability/CVE-2024-49985

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-49985/
Summaries are generated and may contain mistakes; the official description above is the record.