CVE-2026-52951: Linux kernel · drm/xe/dma-buf: handle empty bo and UAF races
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in c473ae25421fddc3dde247ba7b85225b10641d09 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in c473ae25421fddc3dde247ba7b85225b10641d09, 9894731e513019df22a29e5c52f1c98890355ff1, 981bedbbe61364fcc3a3b87ebaf648a66cd07108 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Linux kernel to c473ae25421fddc3dde247ba7b85225b10641d09, 9894731e513019df22a29e5c52f1c98890355ff1, 981bedbbe61364fcc3a3b87ebaf648a66cd07108 or 20a99ea1e2fd720856d6ba497ff26b82c604751f.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
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)
References
- git.kernel.org/stable/c/9894731e513019df22a29e5c52f1c98890355ff1 (opens in a new tab)
- git.kernel.org/stable/c/20a99ea1e2fd720856d6ba497ff26b82c604751f (opens in a new tab)
- git.kernel.org/stable/c/c473ae25421fddc3dde247ba7b85225b10641d09 (opens in a new tab)
- git.kernel.org/stable/c/981bedbbe61364fcc3a3b87ebaf648a66cd07108 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-52951 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2492353 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52951.json (opens in a new tab)