ACPI: video: Fix use-after-free in acpi_video_switch_brightness()
Published Nov 21, 2025
5.5
MEDIUMCVSS 3.1
EPSS 0.19%
Description
The switch_brightness_work delayed work accesses device->brightness and device->backlight, freed by acpi_video_dev_unregister_backlight() during device removal.
If the work executes after acpi_video_bus_unregister_backlight() frees these resources, it causes a use-after-free when acpi_video_switch_brightness() dereferences device->brightness or device->backlight.
Fix this by calling cancel_delayed_work_sync() for each device's switch_brightness_work in acpi_video_bus_remove_notify_handler() after removing the notify handler that queues the work. This ensures the work completes before the memory is freed.
[ rjw: Changelog edit ]
Affected products
-
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
-
- Version 3.17StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<3.17
- Version 5.10.247StatusunaffectedConstraints<=5.10.*
- Version 5.15.197StatusunaffectedConstraints<=5.15.*
- Version 5.4.302StatusunaffectedConstraints<=5.4.*
- Version 6.1.159StatusunaffectedConstraints<=6.1.*
- Version 6.12.58StatusunaffectedConstraints<=6.12.*
- Version 6.17.8StatusunaffectedConstraints<=6.17.*
- Version 6.18StatusunaffectedConstraints<=*
- Version 6.6.117StatusunaffectedConstraints<=6.6.*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
| |||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
Red Hat Enterprise Linux 10
kernel
Fix deferred
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Fix deferred
Red Hat Enterprise Linux 8
kernel-rt
Fix deferred
Red Hat Enterprise Linux 9
kernel
Fix deferred
Red Hat Enterprise Linux 9
kernel-rt
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
A use after free occurred in acpi_video_switch_brightness() because delayed work (switch_brightness_work) could run after its associated device->brightness or device->backlight fields were freed during ACPI video device removal. This bug is locally triggerable (privileged or kernel-context only) and mainly leads to kernel crashes (DoS). It demonstrates a race condition between workqueue cleanup and device teardown.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Jun 16, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
2025–2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.19% (0.00195) | 8.34th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.18% (0.00180) | 7.68th | v5 (v2026.06.15) |
| Nov 21, 2025 | 0.02% (0.00017) | 3.03th | v4 (v2025.03.14) |
References (13)
- https://access.redhat.com/security/cve/CVE-2025-40211 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2416309 Issue Tracking
- https://git.kernel.org/stable/c/293125536ef5521328815fa7c76d5f9eb1635659
- https://git.kernel.org/stable/c/3f803ccf5a0c043e7c8b83f6665b082401fc8bee
- https://git.kernel.org/stable/c/4e85246ec0d019dfba86ba54d841ef6694f97149
- https://git.kernel.org/stable/c/8f067aa59430266386b83c18b983ca583faa6a11
- https://git.kernel.org/stable/c/a63a5b6fb508d78fe57ae3b159d9ef3af7ba80e9
- https://git.kernel.org/stable/c/ba1704316492a0496c69334338ea1fdbf4c2fd34
- https://git.kernel.org/stable/c/bc78a4f51d548c1ccc3d1967c2b394bf687c86e9
- https://git.kernel.org/stable/c/de5fc93275a4a459fe2f7cb746984f2ab3e8292a
- https://lore.kernel.org/linux-cve-announce/2025112140-CVE-2025-40211-465b@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2025-40211
- https://www.cve.org/CVERecord?id=CVE-2025-40211
Change history (0)
No recorded changes yet.