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CVE-2026-52951
drm/xe/dma-buf: handle empty bo and UAF races
Published 2026-06-24 (4 months ago) by the Linux kernel CNA. Subsystem drivers/gpu. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-52951 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.10-1 | Update the kernel and reboot. Fixed in 7.0.10-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
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)
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/gpu/drm/xe/xe_dma_buf.c
- What this is
- INTEL DRM XE DRIVER (Lunar Lake and newer)MAINTAINERS section matched on drivers/gpu/drm/xe/ · intel-xe@lists.freedesktop.org · Supported
- Kernel module
- xe
Check it on the machine
grep -w CONFIG_DRM_XE /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w xePrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixieMnot built on amd64/cloud-amd64, arm64/arm64-16k, arm64/cloud-arm64, armel/rpi, ppc64el/powerpc64le-64k, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/arm64-16k, arm64/cloud-arm64, loong64/loong64, ppc64el/powerpc64le-64k, s390x/s390x
- ?
- not established - no Makefile entry for the affected file
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switch
- CONFIG_DRM_XE
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-06-24 (4 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.18%, higher than 6.9% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/gpu
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.8 | 6.12.91 | 9894731e5130 |
| 6.8 | 6.18.33 | 20a99ea1e2fd |
| 6.8 | 7.0.10 | c473ae25421f |
| 6.8 | 7.1 | 981bedbbe613 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The vulnerable path is reached through local DRM PRIME ioctls on a xe DRM render/primary node, importing a dma-buf fd into the xe driver. There is no network or adjacent protocol exposure.
- AC:LAttack complexity, low
- The bug is a race, but a local attacker can control the import side and can concurrently trigger exporter-side dma-buf movement/eviction notifications. No condition outside attacker control is required beyond a reasonable affected GPU/dma-buf setup.
- PR:LPrivileges required, low
- The PRIME fd-to-handle ioctl is DRM_RENDER_ALLOW and does not require DRM master, root, or CAP_SYS_ADMIN. The attacker needs ordinary local access to the DRM render device/dma-buf-producing process context, which is low privilege.
- UI:NUser interaction, none
- The attacker can perform the required ioctls and concurrent operations directly. No separate victim user action is required.
- S:UScope, unchanged
- The vulnerability is in kernel DRM/dma-buf handling and impacts kernel memory within the same security authority. It is not a VM escape or separate security-scope boundary crossing.
- C:HConfidentiality impact, high
- The flaw includes a use-after-free of a kernel xe buffer object attachment, which can potentially be shaped into kernel memory disclosure. Under the required higher-severity rule for UAFs, confidentiality impact is High.
- I:HIntegrity impact, high
- The UAF/memory-corruption condition can potentially be exploited with heap reuse/spraying to corrupt kernel objects or gain control-flow influence. Under the required higher-severity rule for UAFs, integrity impact is High.
- A:HAvailability impact, high
- The reported and plausible immediate outcomes include NULL pointer dereference, UAF crashes, warnings/oopses, and kernel instability during BO eviction. Kernel crash or hang impact is High.