CVE-2024-38620

What it actually does

The change removes HCI_AMP controller support and the hdev->dev_type field from the Linux kernel Bluetooth HCI subsystem, eliminating differentiation between AMP and primary controllers after BT_HS removal.

Why it matters to the business

Organizations running affected Linux kernel versions may carry unnecessary Bluetooth code that increases maintenance overhead and potential attack surface until the cleanup commit is applied; prevalence across stable kernel trees amplifies the need for prompt updates in embedded and server environments.

How an attack unfolds

No known exploitation path exists; the entry documents a proactive code removal rather than an active flaw that attackers could trigger.

How to fix it

Upgrade the Linux kernel to a version containing commit 5af2e235b0d5b797e9531a00c50058319130e156 or later in the stable trees listed.

How to confirm the fix worked

Confirm the presence of commit 5af2e235b0d5b797e9531a00c50058319130e156 in the kernel source tree and verify that HCI_AMP-related symbols and dev_type handling have been removed from net/bluetooth/hci_core.c and related files.

How to detect it

Examine kernel build logs and source history for references to HCI_AMP or dev_type before the listed commit; no runtime exploitation artifacts are known.

What your security team should do

• Prioritize kernel updates to the fixed commit in all distributions and embedded devices within the next patching cycle.
• Review Bluetooth subsystem configuration to ensure AMP-related options are disabled where possible until patches are deployed.
• Monitor kernel changelogs for related Bluetooth cleanups that may affect older stable branches.