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Fencer Vulns
high 7.8

CVE-2026-68274 json

drm/xe/guc: Fix buffer overflow in steered register list allocation

published 2026-08-10 2 mo ago modified 2026-10-19 20 d ago also EUVD-2026-55375

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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

drm/xe/guc: Fix buffer overflow in steered register list allocation

The size calculation for the steered register extarray uses only the geometry DSS mask (g_dss_mask) to determine the number of entries to allocate:

total = bitmap_weight(gt->fuse_topo.g_dss_mask, ...) * steer_reg_num;

However, the filling loop uses for_each_dss_steering(), which iterates over for_each_dss(), defined as the union of g_dss_mask and c_dss_mask (geometry + compute DSS). On platforms with compute-only DSS bits, the loop writes past the allocated buffer, corrupting adjacent slab objects.

This manifests as list_del corruption and SLUB redzone overwrites during drm_managed_release on device unbind, since the overflow corrupts the drmres list_head of neighboring allocations.

Fix by computing the allocation size using the union of both DSS masks, matching the iteration pattern of for_each_dss_steering().

-- v2: - use bitmap_weighted_or() (Zhanjun)

(cherry picked from commit 0a78a44f4901aa6c9263e66be7fce02282f1109f)

Patch / fix

  • Linux Linux 6.18.44, 7.1.6, 7.2
  • linux Debian 14 7.1.6-1

debian advisories DEBIAN-CVE-2026-68274

  • 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-2026-68274

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

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-2026-68274 updated cvss 7.8

kernel: drm/xe/guc: Fix buffer overflow in steered register list allocation

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel 6.12.0-211.46.1.el10_2
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +2 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +30 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal Red Hat Enterprise Linux for NVIDIA 26 kernel 6.12.0-211.46.1.el10_2 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    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

0.15% chance of exploitation in the next 30 days, higher than 4% 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

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