CVE-2024-23848

What it actually does

Use-after-free condition in cec_queue_msg_fh allows a local process to reference freed memory while handling CEC messages through cec-adap.c and cec-api.c interfaces.

Why it matters to the business

Affected Linux systems may experience kernel instability or crashes when CEC hardware or related media functions are used, leading to service interruptions on devices with consumer electronics control support.

How an attack unfolds

An attacker with local access crafts or sends specific CEC messages that trigger the use-after-free path in the kernel's CEC queue handling, resulting in denial of service.

How to fix it

Upgrade the Linux kernel to a version newer than 6.7.1 that contains the fix for the use-after-free in cec_queue_msg_fh; apply distribution-specific security patches as they become available.

How to confirm the fix worked

Verify the running kernel version exceeds 6.7.1 and confirm the presence of the corrected cec_queue_msg_fh implementation in cec-adap.c and cec-api.c; test CEC functionality for stability.

Typical attack path

1. Obtain local user access on a system running an affected Linux kernel version
2. Interact with CEC device nodes or API to queue crafted messages
3. Trigger the race or reference after free in cec_queue_msg_fh
4. Cause kernel panic or system hang

How to detect it

Examine kernel logs for oops, panic, or use-after-free warnings referencing cec_queue_msg_fh, cec-adap.c, or cec-api.c; correlate with processes accessing CEC device files.

What your security team should do

• Prioritize kernel updates on systems exposing CEC or media devices
• Monitor for kernel oops or panic logs related to cec drivers
• Restrict unprivileged access to /dev/cec* nodes where feasible
• Review EPSS and exploit maturity data periodically given the low but stable score