CVE-2023-52500

What it actually does

Failure to free tags allocated for OPC_INB_SET_CONTROLLER_CONFIG responses in the pm80xx SCSI driver results in a resource leak within the Linux kernel.

Why it matters to the business

Linux systems using pm80xx-based storage controllers may experience gradual exhaustion of tag resources, potentially affecting storage operations and requiring restarts over extended periods.

How an attack unfolds

An attacker with local access or the ability to influence SCSI command flows triggers repeated OPC_INB_SET_CONTROLLER_CONFIG commands; the kernel allocates tags but never releases them on response, leading to accumulation.

How to fix it

Update the Linux kernel to a version containing commit 2afd8fcee0c4d65a482e30c3ad2a92c25e5e92d4 or later equivalent stable branch fix for the pm80xx driver.

How to confirm the fix worked

Verify the running kernel includes the referenced commit or check for absence of the tag-leak condition via code review or updated driver behavior under test loads.

Typical attack path

1. Obtain local execution or SCSI command injection capability on affected kernel
2. Issue or force OPC_INB_SET_CONTROLLER_CONFIG commands to pm80xx controller
3. Observe repeated tag allocation without corresponding frees in driver response path

How to detect it

Review kernel logs and driver traces for pm80xx tag allocation patterns or resource warnings; examine system call or SCSI command histories for repeated controller config operations.

What your security team should do

• Prioritize kernel upgrades on systems with pm80xx hardware
• Monitor tag allocation and SCSI resource usage metrics for anomalies
• Apply updates within standard patch cycles given low EPSS and absence from KEV