Overview
About vulnerability
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 ]
Details
- Affected product:
- Oracle Linux 7 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel-uek @ 5.4.17 (+2 more)
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 ]