CVE-2024-38629

What it actually does

The vulnerability is a use-after-free in the Linux kernel idxd DMA engine driver where file_ida allocated on cdev open can be accessed via ida_free after ida_destroy during WQ cdev removal, leading to a kernel panic.

Why it matters to the business

Affected Linux systems may experience sudden crashes and service interruptions when the idxd driver is in use, increasing downtime risk on servers or appliances relying on this hardware feature.

How an attack unfolds

An attacker with local access performs cdev open/release operations while concurrently triggering WQ cdev removal, causing ida_free to execute after the IDA has been destroyed.

How to fix it

Upgrade the linux kernel package on Debian 13 to version 6.6.15-1 or later.

How to confirm the fix worked

Confirm the running kernel version meets or exceeds 6.6.15-1 and verify that cdev open/release sequences complete without kernel panics.

Typical attack path

1. Gain local access to a system using the idxd driver
2. Open the character device to allocate file_ida
3. Trigger removal of the WQ cdev
4. Perform release operation that calls ida_free on the destroyed structure

How to detect it

Inspect system logs and kernel crash dumps for panic entries involving ida_destroy or file_ida access after free during cdev release.

What your security team should do

• Apply the kernel update to 6.6.15-1 or newer on all Debian 13 systems using the idxd driver
• Monitor kernel logs for panic messages referencing ida or file_ida
• Restrict local access to systems exposing idxd cdev interfaces until patched