Linux Kernel ACPI Button Handler Leak Vulnerability

A vulnerability in the Linux kernel's ACPI button handling has been addressed. The issue arose because a previous commit changed the notification handler type for ACPI buttons but did not update the corresponding removal function. This oversight led to a leak of the notification handler after the driver was removed, potentially causing a kernel crash if an ACPI notification was received for the device after the driver had been detached. Additionally, this leak could interfere with re-probing the device with the same driver. The vulnerability affects Linux kernel versions 6.15 and later.

Impact

Failing to properly manage the ACPI notification handler can lead to kernel crashes, especially if notifications are received after the driver has been removed. This mishandling can also cause issues when trying to reattach the driver to the device.

Remediation

Users can upgrade to the latest version of the Linux kernel to address this vulnerability. The specific commit that resolves the issue is available in the Linux kernel stable tree.