CVE-2022-48657

What it actually does

Integer overflow when cpufreq_get_hw_max_freq() (unsigned int kHz) is multiplied by 1000 before being passed as u64 Hz to freq_inv_set_max_ratio() inside amu_fie_setup() on arm64.

Why it matters to the business

Local users on arm64 Linux systems can trigger incorrect CPU frequency scaling, leading to performance degradation, instability, or potential elevation of privileges; urgency is low given absent KEV listing and flat EPSS trend.

How an attack unfolds

A local attacker invokes code paths that call amu_fie_setup() with hardware-reported max frequencies large enough to overflow the 32-bit multiplication, resulting in a corrupted frequency ratio used by the scheduler.

How to fix it

Upgrade chromium on Debian 11 to version 107.0.5304.121-1~deb11u1 or later; apply the upstream kernel commit that changes the multiplication to 1000ULL.

How to confirm the fix worked

Confirm the installed kernel contains the amu_fie_setup() fix (search for 1000ULL) and verify chromium package version matches or exceeds 107.0.5304.121-1~deb11u1 on Debian 11 systems.

Typical attack path

1. Obtain local shell or userland execution on an arm64 Linux host
2. Trigger cpufreq hardware frequency queries that reach amu_fie_setup()
3. Supply or wait for a max-frequency value whose kHz representation overflows when multiplied by 1000
4. Leverage resulting incorrect AMU frequency-invariant data for further scheduler or privilege-escalation attacks

How to detect it

Review kernel logs for amu_fie_setup or cpufreq frequency-invariant errors; examine scheduler and cpufreq tracepoints around large max-frequency values; no public exploitation artifacts are known.

What your security team should do

• Apply the listed chromium package update on all Debian 11 arm64 systems immediately
• Audit arm64 kernels for the 1000ULL multiplication change and backport if chromium update alone is insufficient
• Monitor EPSS and KEV status weekly given the 902-day publication age