CVE-2022-1998

What it actually does

Use-after-free vulnerability in Linux kernel fsnotify subsystem triggered when copy_info_records_to_user() fails during copy_event_to_user() processing, allowing memory corruption by a local user.

Why it matters to the business

Local attackers on affected Linux systems can cause crashes or gain elevated privileges, leading to downtime, data compromise, and potential full system takeover on servers, workstations, and embedded devices using vulnerable kernels.

How an attack unfolds

An attacker with local access crafts input to trigger fsnotify events and forces a failure path in copy_event_to_user() that leaves dangling pointers, then reuses the freed memory to corrupt kernel structures for privilege escalation or denial of service.

How to fix it

Apply the latest available Linux kernel security updates from distribution vendors for all affected products including Fedora, Red Hat Enterprise Linux, and NetApp storage systems; rebuild and reboot into patched kernels; disable unnecessary fsnotify usage where feasible as a temporary mitigation.

How to confirm the fix worked

Verify kernel version against vendor advisories; inspect kernel changelog or git history for fsnotify copy_event_to_user fixes; run automated vulnerability scanners configured with current CVE data; confirm no crash dumps reference the vulnerable copy_info_records_to_user path after patching.

Typical attack path

1. Obtain local shell access on target system
2. Trigger file system notify events via monitored paths or descriptors
3. Induce failure in copy_info_records_to_user() call path
4. Reuse freed kernel memory objects to corrupt process credentials or kernel data
5. Escalate to root or trigger kernel panic

How to detect it

Review kernel logs and crash dumps for references to fsnotify and copy_event_to_user failures; correlate with authentication or privilege escalation events; monitor for unexpected process ownership changes or system instability on Linux hosts.

What your security team should do

• Prioritize kernel updates across all Linux endpoints within 30 days given public disclosure age
• Restrict local user accounts and monitor for unusual privilege changes
• Enable kernel hardening features such as SMEP, SMAP, and KASLR if not already active
• Audit systems for custom fsnotify usage that could increase exposure
• Incorporate kernel exploit detection rules into EDR and SIEM platforms