CVE-2024-44937

Technical Description

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

platform/x86: intel-vbtn: Protect ACPI notify handler against recursion

Since commit e2ffcda16290 ("ACPI: OSL: Allow Notify () handlers to run on

all CPUs") ACPI notify handlers like the intel-vbtn notify_handler() may

run on multiple CPU cores racing with themselves.

This race gets hit on Dell Venue 7140 tablets when undocking from

the keyboard, causing the handler to try and register priv->switches_dev

twice, as can be seen from the dev_info() message getting logged twice:

[ 83.861800] intel-vbtn INT33D6:00: Registering Intel Virtual Switches input-dev after receiving a switch event

[ 83.861858] input: Intel Virtual Switches as /devices/pci0000:00/0000:00:1f.0/PNP0C09:00/INT33D6:00/input/input17

[ 83.861865] intel-vbtn INT33D6:00: Registering Intel Virtual Switches input-dev after receiving a switch event

After which things go seriously wrong:

[ 83.861872] sysfs: cannot create duplicate filename '/devices/pci000

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References