# CVE-2026-98510: drm/xe/vm: nuke PTs only after unlinking contested VMAs

> A race condition in the Linux kernel's Xe GPU driver causes a NULL pointer dereference, leading to a system crash when shared buffer objects are evicted concurrently.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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:** 18 Oct 2026
- **Updated:** 24 Oct 2026
- **Also known as:** BELL-CVE-2026-98510, DEBIAN-CVE-2026-98510, GHSA-p8r6-wxq7-5fv3, UBUNTU-CVE-2026-98510

## What is CVE-2026-98510?

CVE-2026-98510 is a high-severity vulnerability in Linux, published on 18 Oct 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/xe/vm: nuke PTs only after unlinking contested VMAs

In xe_vm_close_and_put(), external-BO VMAs are queued on the contested
list for deferred destruction via xe_vma_destroy_unlocked(). However,
xe_vm_pt_destroy() was previously invoked before processing contested
VMAs, destroying vm->pt_root while those VMAs were still linked to their
respective buffer objects (vm_bo->list.gpuva).

If a concurrent thread evicts one of those shared buffer objects,
xe_bo_trigger_rebind() holding only bo->resv walks the BO's VMAs and, in
fault mode, calls xe_vm_invalidate_vma() -> xe_pt_zap_ptes(). Because
vm->pt_root[tile->id] is already NULL, dereferencing pt->level causes a
NULL ptr deref.

Fix this by deferring xe_vm_free_scratch() and xe_vm_pt_destroy() until
after all contested VMAs have been unlinked and destroyed.

User is reporting hitting a NULL ptr deref in xe_pt_zap_ptes(), which
could be explained by this race.

(cherry picked from commit c2863648959489767f08892fd6e90577d2ea0b6a)

## Which versions are affected by CVE-2026-98510?


## How do I fix CVE-2026-98510?

Apply the vendor's patch.

## Is CVE-2026-98510 being exploited?

There is no known exploitation of CVE-2026-98510 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98510 and fix it if it is affected.

What it is: CVE-2026-98510 is a high-severity vulnerability in Linux, published on 18 Oct 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-2026-98510 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-2026-98510/ (Markdown: https://insights.sbomify.com/CVE-2026-98510/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98510
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98510
- OSV: https://osv.dev/vulnerability/CVE-2026-98510

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98510/
Summaries are generated and may contain mistakes; the official description above is the record.