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Fencer Intel
high 8.8

CVE-2026-63863 json

drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()

published 3mo ago modified 16d ago also EUVD-2026-45547

cvss
8.8
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/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()

There is a unbalanced lock/unlock to gpusvm notifier lock: [ 931.045868] ===================================== [ 931.046509] WARNING: bad unlock balance detected! [ 931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G U [ 931.048150] ------------------------------------- [ 931.048790] kworker/u5:0/51 is trying to release lock (&gpusvm->notifier_lock) at: [ 931.049801] [<ffffffffa090c0d8>] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper] [ 931.050802] but there are no more locks to release! [ 931.051463]

The drm_gpusvm_notifier_unlock() sits under err_free label and the first jump to err_free is just before calling the drm_gpusvm_notifier_lock() causing unbalanced unlock.

Patch / fix

  • Linux Linux 7.0.10, 7.1
  • linux Debian 14 7.0.10-1

debian advisories DEBIAN-CVE-2026-63863

  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1008.8
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1003.4
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1010.10
  • linux-azure Ubuntu 26.04 LTS 7.0.0-1010.10
  • linux-raspi Ubuntu 26.04 LTS 7.0.0-1015.15
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-28.28.1

ubuntu advisories UBUNTU-CVE-2026-63863

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

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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-2026-63863 updated cvss 5.5

kernel: drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: workaround, no fix available “Fix deferred”
  • 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-selftests-internal Red Hat Enterprise Linux 10 kernel
    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
26d ago

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel 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.