CVE-2023-52689

What it actually does

Missing mutex protection around access to meter_level_map[] in scarlett2_meter_ctl_get() allows a data race when reading meter levels in the ALSA scarlett2 driver.

Why it matters to the business

Low-probability local inconsistency in reported audio meter values on affected Linux systems; minimal operational disruption given low exploitability and age of the issue.

How an attack unfolds

An attacker with local access triggers concurrent calls to meter control get while the driver updates levels, relying on the unprotected map access to produce inconsistent or stale readings; no known threat actors or ransomware use.

How to fix it

Update to a kernel containing commit 74e3de7cdcc31ce75ab42350ae0946eff62a2da2 or later; for listed Ubuntu Wireshark packages apply the referenced fixed versions such as 1.12.1+g01b65bf-4+deb8u11ubuntu0.14.04.1 or 2.0.2+ga16e22e-1.

How to confirm the fix worked

Confirm presence of the mutex lock around meter_level_map[] access in scarlett2_meter_ctl_get() and verify the running kernel includes the listed fix commit.

Typical attack path

1. Obtain local user access on a system using the scarlett2 ALSA driver
2. Trigger concurrent meter level queries and updates
3. Observe or influence race condition outcome in meter data

How to detect it

Review kernel logs and driver traces for concurrent meter access patterns or unexpected level map behavior on systems using scarlett2 hardware; no public exploitation artifacts known.

What your security team should do

• Apply the kernel or package updates matching the fixed versions provided
• Prioritize systems exposing ALSA scarlett2 audio interfaces
• Monitor EPSS and KEV status for any future increase in activity