# CVE-2026-89811: drm/amdkfd: Add TLB flush after MES queue eviction/suspension

> A race condition in the AMD KFD driver causes GPU hangs during memory migration when XNACK mode is enabled, requiring a TLB flush fix.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101690, BELL-CVE-2026-89811, DEBIAN-CVE-2026-89811, GHSA-vph6-3qcj-jq9w, UBUNTU-CVE-2026-89811

## What is CVE-2026-89811?

CVE-2026-89811 is a high-severity vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

drm/amdkfd: Add TLB flush after MES queue eviction/suspension

MES (Micro Engine Scheduler) does not perform heavy-weight TLB
invalidation after unmapping queues, unlike HWS which does this
automatically. This causes a race condition where in-flight DMA
descriptors can access memory that has been unmapped, leading to page
faults and GPU queue hangs during SVM page migration.

The issue manifests as KFDSVMRangeTest.MultiThreadMigrationTest
failures on gfx1151 (Strix Point) with XNACK mode 1 enabled - the GPU
compute queue hangs with packets submitted but never consumed.

Add kfd_flush_tlb() calls after MES queue removal in two locations:
- evict_process_queues_cpsch(): after all queues removed during eviction
- suspend_queues(): after debug/criu queue suspension (with mem_fence barrier)

This ensures all in-flight memory accesses from unmapped queues are
flushed before memory is freed or migrated.

(cherry picked from commit f5c4f88e0f9c45a8fb9dfac0c1df726c95e41b77)

## Which versions are affected by CVE-2026-89811?


## How do I fix CVE-2026-89811?

Apply the vendor's patch.

## Is CVE-2026-89811 being exploited?

There is no known exploitation of CVE-2026-89811 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89811 and fix it if it is affected.

What it is: CVE-2026-89811 is a high-severity vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-89811 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-89811/ (Markdown: https://insights.sbomify.com/CVE-2026-89811/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89811
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89811
- OSV: https://osv.dev/vulnerability/CVE-2026-89811

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89811/
Summaries are generated and may contain mistakes; the official description above is the record.