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Fencer Vulns
high 7.8

CVE-2026-68266 json

drm/xe: Hold a dma-buf reference for imported BOs

published 2026-08-10 2 mo ago modified 2026-10-19 20 d ago also EUVD-2026-55367

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

drm/xe: Hold a dma-buf reference for imported BOs

An imported dma-buf BO is created as a ttm_bo_type_sg BO whose reservation object is the exporter's dma_buf->resv. The importer, however, only takes a dma-buf reference after a successful dma_buf_dynamic_attach(). Until then nothing keeps the exporter alive, so if the exporter is freed while the BO still references its resv, a later access to that resv is a use-after-free:

Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b9c Workqueue: ttm ttm_bo_delayed_delete [ttm] RIP: 0010:mutex_can_spin_on_owner+0x3f/0xc0

This can be reached on two paths:

- dma_buf_dynamic_attach() fails, or - ttm_bo_init_reserved() fails during BO creation.

In both cases the BO already has bo->base.resv pointing at the exporter resv, and sg BOs are always torn down via ttm_bo_delayed_delete(), which locks bo->base.resv asynchronously - potentially after the exporter has been freed.

Take the dma-buf reference in xe_bo_init_locked(), before ttm_bo_init_reserved(), so it also covers a creation failure there, and release it in xe_ttm_bo_destroy(). The reference is held for the whole BO lifetime, keeping the shared resv alive on every path.

v2: - Reworked the fix to avoid creating the imported sg BO before dma_buf_dynamic_attach() succeeds. - Attach with importer_priv == NULL and make invalidate_mappings ignore incomplete imports.

v3: - Dropped the xe-side reordering approach since importer_priv must be valid when dma_buf_dynamic_attach() publishes the attachment. - Per Christian's suggestion on the v1 thread, keyed the check on import_attach rather than removing the sg guard entirely. - Fixes both xe and amdgpu in a single TTM patch.

v4: - Moved import_attach check to after dma_resv_copy_fences() so fences are copied before returning for successful imports (Thomas). - Removed exporter-alive claim from commit message (Thomas).

v5: - Add drm/xe patch to keep imported sg BOs off the LRU before attach succeeds; the TTM fix alone is not sufficient for xe if the BO is already LRU-visible. (Thomas) v4 patch: https://patchwork.freedesktop.org/patch/736663/?series=169129&rev=2 - Patch 1 (drm/ttm) carries Christian's Reviewed-by from v4.

v6: - Reworked the fix based on Thomas' suggestion. Instead of the TTM resv individualization (v1-v5) plus the xe off-LRU/placement handling (v5), just hold a dma-buf reference for the imported BO lifetime so the shared resv can never be freed while the BO still references it. Single xe patch, no TTM change. (Thomas) - Take the reference in xe_bo_init_locked() before ttm_bo_init_reserved() so a TTM creation failure is covered too (Thomas). - Dropped the v5 series (drm/ttm + drm/xe off-LRU); the off-LRU approach also regressed in CI BAT via ttm_bo_pipeline_gutting() creating a ghost BO that outlived the exporter. Link to v5: https://patchwork.freedesktop.org/series/169984/

v7: - Move changelog above --- so it stays in the commit message. - Reorder changelog entries oldest-to-newest. (Thomas)

(cherry picked from commit 3516f3fae6be35642f8f06f8a218da6425c0306a)

Patch / fix

  • Linux Linux 6.12.103, 6.18.42, 7.1.6, 7.2
  • linux Debian 13 6.12.105-1
  • linux Debian 14 7.1.6-1
  • linux-6.12 Debian 12 6.12.107-1~deb12u1

debian advisories DEBIAN-CVE-2026-68266

  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1008.9
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1015.15
  • linux-azure Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-38.38.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1013.13

ubuntu advisories UBUNTU-CVE-2026-68266

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-687.52.1.el9_8
  • rv RHEL 9 5.14.0-687.52.1.el9_8
  • perf RHEL 9 5.14.0-687.52.1.el9_8
  • rtla RHEL 9 5.14.0-687.52.1.el9_8
  • libperf RHEL 9 5.14.0-687.52.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.52.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.52.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.52.1.el9_8

red hat advisories RHSA-2026:71700RHSA-2026:71602

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.84.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.84.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.84.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.84.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1.150700.17.47.1

suse advisories SUSE-SU-2026:4706-1SUSE-SU-2026:4640-1SUSE-SU-2026:24197-1SUSE-SU-2026:24184-1SUSE-SU-2026:24235-1SUSE-SU-2026:24179-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.39.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.39.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.39.1

opensuse advisories openSUSE-SU-2026:22091-1

  • kernel AlmaLinux 9 5.14.0-687.52.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.52.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.52.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.52.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.52.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.52.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.52.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.52.1.el9_8

almalinux advisories ALSA-2026:71700ALSA-2026:71602

  • kernel Rocky Linux 10 6.12.0-211.60.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.52.1.el9_8

rocky linux advisories RLSA-2026:71602RLSA-2026:71700

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-68266 updated cvss 7.0

kernel: drm/xe: Hold a dma-buf reference for imported BOs

  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.52.1.el9_8, perf 5.14.0-687.52.1.el9_8, rtla 5.14.0-687.52.1.el9_8, python3-perf 5.14.0-687.52.1.el9_8, kernel-devel-matched 5.14.0-687.52.1.el9_8, kernel-64k-devel-matched 5.14.0-687.52.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:71700
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.60.1.el10_2, perf 6.12.0-211.60.1.el10_2, rtla 6.12.0-211.60.1.el10_2, python3-perf 6.12.0-211.60.1.el10_2, kernel-devel-matched 6.12.0-211.60.1.el10_2, kernel-64k-devel-matched 6.12.0-211.60.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:71602
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.52.1.el9_8, kernel-64k 5.14.0-687.52.1.el9_8, kernel-core 5.14.0-687.52.1.el9_8, kernel-tools 5.14.0-687.52.1.el9_8, kernel-modules 5.14.0-687.52.1.el9_8, kernel-64k-core 5.14.0-687.52.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:71700
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.60.1.el10_2, kernel-64k 6.12.0-211.60.1.el10_2, kernel-core 6.12.0-211.60.1.el10_2, kernel-tools 6.12.0-211.60.1.el10_2, kernel-modules 6.12.0-211.60.1.el10_2, kernel-64k-core 6.12.0-211.60.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:71602
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.52.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.52.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.52.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.52.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.52.1.el9_8
    fixed: vendor fix RHSA-2026:71700
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.60.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.60.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.60.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.60.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.60.1.el10_2
    fixed: vendor fix RHSA-2026:71602
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.52.1.el9_8, kernel-rt-64k 5.14.0-687.52.1.el9_8, kernel-rt-core 5.14.0-687.52.1.el9_8, kernel-rt-modules 5.14.0-687.52.1.el9_8, kernel-rt-64k-core 5.14.0-687.52.1.el9_8, kernel-rt-debug-core 5.14.0-687.52.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:71700
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.60.1.el10_2, kernel-rt-64k 6.12.0-211.60.1.el10_2, kernel-rt-core 6.12.0-211.60.1.el10_2, kernel-rt-modules 6.12.0-211.60.1.el10_2, kernel-rt-64k-core 6.12.0-211.60.1.el10_2, kernel-rt-debug-core 6.12.0-211.60.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:71602
show 3 more
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.52.1.el9_8, kernel-rt-core 5.14.0-687.52.1.el9_8, kernel-rt-modules 5.14.0-687.52.1.el9_8, kernel-rt-debug-core 5.14.0-687.52.1.el9_8, kernel-rt-modules-core 5.14.0-687.52.1.el9_8, kernel-rt-debug-modules 5.14.0-687.52.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:71700
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.60.1.el10_2, kernel-rt-core 6.12.0-211.60.1.el10_2, kernel-rt-modules 6.12.0-211.60.1.el10_2, kernel-rt-debug-core 6.12.0-211.60.1.el10_2, kernel-rt-modules-core 6.12.0-211.60.1.el10_2, kernel-rt-debug-modules 6.12.0-211.60.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:71602
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.