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

ACPI: video: Fix use-after-free in acpi_video_switch_brightness()

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 ]
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 22 Nov 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Fri, 21 Nov 2025 10:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ACPI: video: Fix use-after-free in acpi_video_switch_brightness() 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 ]
Title ACPI: video: Fix use-after-free in acpi_video_switch_brightness()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-11-21T10:21:36.438Z

Reserved: 2025-04-16T07:20:57.179Z

Link: CVE-2025-40211

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-11-21T11:15:49.513

Modified: 2025-11-21T15:13:13.800

Link: CVE-2025-40211

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-11-21T00:00:00Z

Links: CVE-2025-40211 - Bugzilla

cve-icon OpenCVE Enrichment

No data.