CVE-2026-23142

What it actually does

On DAMON sysfs scheme directory setup failure after access_pattern subdirectory creation, subdirectories are not removed, leaving the sysfs interface in a broken state with leaked kernel memory until reboot.

Why it matters to the business

Local users or processes triggering the failure condition can force a system reboot to restore monitoring functionality, causing unplanned downtime and potential loss of DAMON-based memory management in production Linux environments.

How an attack unfolds

An attacker with local access creates a DAMOS scheme via sysfs that intentionally fails after the access_pattern directory is set up, leaving dangling subdirectories that break the entire DAMON sysfs interface and leak memory; repeated triggers may necessitate reboot.

How to fix it

Update the Linux kernel to the fixed commit ae8ac0066b48ed957bdcab58f0d3543549c57a29 or later stable release containing the cleanup logic for access_pattern subdirectories on scheme setup failure.

How to confirm the fix worked

Verify the running kernel contains commit ae8ac0066b48ed957bdcab58f0d3543549c57a29; attempt to reproduce the original failure path and confirm directories are properly cleaned up with no leaked objects or broken sysfs entries.

Typical attack path

1. Obtain local user or process execution on the target Linux system
2. Write to DAMON sysfs files to create a scheme directory that triggers setup failure after access_pattern subdir creation
3. Observe resulting broken sysfs state and memory leak
4. Repeat to force operational impact or reboot requirement

How to detect it

Inspect kernel logs for DAMON sysfs errors during scheme creation; look for evidence of unreleased sysfs directories or memory leaks via slabinfo or kmemleak after failed scheme setups.

What your security team should do

• Prioritize kernel upgrade to the fixed version on all systems using DAMON sysfs interface
• Restrict local access to sysfs DAMON controls for untrusted users until patched
• Monitor for unexpected DAMON sysfs errors or memory pressure that may indicate exposure