CVE-2021-47329

What it actually does

Resource leak in megaraid_sas driver when scsi_add_host() or megasas_start_aen() fails during PCI probe, leaving allocated resources uncleaned.

Why it matters to the business

Systems with MegaRAID SAS controllers risk gradual resource exhaustion or instability during driver initialization failures, potentially disrupting storage availability.

How an attack unfolds

An attacker with local access triggers conditions causing probe failure in the megaraid_sas driver, resulting in leaked resources that degrade system stability over repeated attempts.

How to fix it

Update to a Linux kernel containing the fix that properly cleans up resources on scsi_add_host() or megasas_start_aen() failure.

How to confirm the fix worked

Verify kernel version includes the megaraid_sas probe cleanup commit; test driver probe paths under failure injection to confirm no leaks.

Typical attack path

1. Obtain local access to target system
2. Induce or wait for PCI probe failure conditions in megaraid_sas
3. Exploit resulting resource leak for denial of service

How to detect it

Review kernel logs for megaraid_sas probe failure messages without corresponding cleanup; correlate with resource usage spikes on affected systems.

What your security team should do

• Prioritize kernel updates on systems using megaraid_sas hardware
• Monitor for repeated driver probe failures in system logs
• Apply defense-in-depth local access controls