CVE-2026-52951

CVE-2026-52951 is a high-severity vulnerability with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

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)

Frequently asked questions

What is CVE-2026-52951?
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)
How severe is CVE-2026-52951?
CVE-2026-52951 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-52951 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-52951?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-52951 have an EU (EUVD) identifier?
Yes. CVE-2026-52951 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38819.
When was CVE-2026-52951 published?
CVE-2026-52951 was published on 2026-06-24 and last updated on 2026-06-30.

References

Other CWE-476 (NULL Pointer Dereference) vulnerabilities

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