CVE-2024-27051

What it actually does

Missing validation of cpufreq_cpu_get return value leading to potential NULL pointer dereference in the brcmstb-avs-cpufreq driver.

Why it matters to the business

May cause kernel instability or crashes on affected Linux systems using Broadcom STB hardware, interrupting CPU performance management and requiring reboots or recovery.

How an attack unfolds

An attacker with local access triggers the cpufreq code path where cpufreq_cpu_get returns NULL, resulting in a kernel dereference fault. No confirmed exploitation by named threat actors or ransomware campaigns has been observed.

How to fix it

Update the Linux kernel to include commit 9127599c075caff234359950117018a010dd01db from the stable repository.

How to confirm the fix worked

Inspect the brcmstb-avs-cpufreq source for the added NULL check after cpufreq_cpu_get and confirm the updated commit is present in the running kernel.

Typical attack path

1. Obtain local access to a vulnerable Linux kernel system
2. Invoke or wait for cpufreq_cpu_get to return NULL in the brcmstb-avs-cpufreq driver
3. Trigger NULL dereference to induce kernel panic or denial of service

How to detect it

Review kernel logs and oops reports for entries referencing cpufreq or brcmstb-avs-cpufreq around the time of any crashes.

What your security team should do

• Apply the referenced kernel commit or newer stable release to all affected systems
• Prioritize patching in environments with Broadcom STB hardware
• Monitor kernel logs for related oops or panic events during the update window