CVE-2024-42116

What it actually does

The igc driver calls igc_ptp_init() before register_netdev(), causing netdev_info() to operate on a partially uninitialized net_device structure and emit log messages containing uninitialized kernel data.

Why it matters to the business

System boot logs may contain confusing or unexpected device entries, and in rare cases minor kernel memory contents could appear in logs accessible to local users or monitoring systems.

How an attack unfolds

An attacker with local log access observes the malformed PHC-added message emitted during successful igc probe; no active exploitation path exists beyond passive observation of the uninitialized values.

How to fix it

Update to a fixed kernel package: Debian 12 users install linux-image version 6.1.98-1 or newer; Debian 13 users install linux-image version 6.9.9-1 or newer. Reboot after installation.

How to confirm the fix worked

After upgrade, trigger igc probe and confirm the log line now shows the correct interface name (for example 'eth0: PHC added') instead of the uninitialized placeholder.

Typical attack path

1. Load or trigger igc module probe on affected kernel
2. Observe kernel log containing '(unnamed net_device) (uninitialized)'
3. Extract any uninitialized bytes present in the log line

How to detect it

Search kernel logs and dmesg output for the literal string '(unnamed net_device) (uninitialized)' emitted during igc device probe.

• (unnamed net_device) (uninitialized)

What your security team should do

• Apply the fixed kernel packages immediately on all systems using the igc driver
• Monitor boot logs for the uninitialized net_device string until patches are deployed
• Prioritize systems that expose kernel logs to untrusted users