CVE-2024-46856

What it actually does

Uninitialized private data pointer for DP83825 PHY models causes NULL pointer dereference in dp8382x_config_init() and dp83822_set_wol() when those functions are invoked.

Why it matters to the business

Systems using affected network hardware may experience unexpected kernel crashes or instability, leading to downtime and potential loss of network connectivity until the kernel is updated.

How an attack unfolds

An attacker with local access or the ability to trigger PHY initialization and wake-on-LAN operations on DP83825 hardware can cause the kernel to dereference a NULL pointer, resulting in a crash.

How to fix it

Update the Linux kernel to a version containing commit 67b61e2f4c9c5df97a9a2ef7a1fe35eae00531f4 or later; for Traefik users ensure version 2.6.1 or newer is deployed if the component is in use.

How to confirm the fix worked

Verify the running kernel includes commit 67b61e2f4c9c5df97a9a2ef7a1fe35eae00531f4; inspect PHY driver source to confirm dp8382x_probe initializes private data for all supported models.

Typical attack path

1. Identify systems with DP83825 PHY hardware
2. Trigger PHY probe or configuration paths that call dp8382x_config_init or dp83822_set_wol
3. Cause NULL pointer dereference leading to kernel panic

How to detect it

Review kernel logs for NULL pointer dereference oops mentioning dp8382x_config_init, dp83822_set_wol, or DP83825; correlate with hardware enumeration of DP83825 PHYs.

• dp8382x_config_init
• dp83822_set_wol
• NULL pointer dereference
• dp83825

What your security team should do

• Prioritize kernel updates on all systems containing DP8382x PHYs
• Monitor for kernel oops and panics referencing dp83822 or dp8382x functions
• Test updated kernels in staging environments before broad deployment