Linux Kernel watch_queue Subsystem Out-of-Bounds Write Vulnerability (CVE-2022-0995) Advisory
Executive & SecOps Summary
SECOPS ASSESSMENTLinux kernel versions from 5.8 up to 5.17-rc8 utilizing the watch_queue event notification subsystem.
A local unprivileged attacker can overwrite kernel state memory, potentially leading to local privilege escalation (LPE) to root or system denial of service (DoS).
Apply the latest kernel security patches immediately, or restrict unprivileged user namespaces as a temporary mitigation.
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Kernel Patch Installation
The recommended remediation is to upgrade the Linux kernel to a patched version.
Ubuntu / Debian systems:
sudo apt update
sudo apt-get install --only-upgrade linux-image-generic
sudo rebootRHEL / Rocky Linux systems:
sudo dnf update kernel
sudo reboot2. Temporary Mitigation (If patching is not immediately possible)
You can mitigate the risk by disabling unprivileged user namespaces, which restricts the ability of local users to trigger the vulnerable code path.
# Disable unprivileged user namespaces
sudo sysctl -w kernel.unprivileged_userns_clone=0
# Persist the configuration
echo "kernel.unprivileged_userns_clone=0" | sudo tee -a /etc/sysctl.d/99-disable-userns.confBlock Kernel Privilege Escalation & Ransomware Payloads Before You Can Reboot
Protect unpatched Windows, Linux, and macOS workloads against in-memory exploitation and lateral movement with autonomous EDR.
Technical Root Cause & Exploitation Mechanics
This vulnerability (CVE-2022-0995) is an Out-of-Bounds (OOB) memory write flaw (CWE-787) residing in the Linux kernel's watch_queue event notification subsystem.
By sending specially crafted system calls (ioctl) during the configuration of watch_queue filters, a local attacker can bypass boundary checks and overwrite critical kernel heap memory. Since this vulnerability is listed in the CISA KEV catalog and public exploits are readily available, it poses a severe threat. Attackers who have gained initial local access can leverage this flaw to escape sandboxes and obtain full administrative (root) privileges.
Official Vendor Advisories & References
An out-of-bounds (OOB) memory write flaw was found in the Linux kernel’s watch_queue event notification subsystem. This flaw can overwrite parts of the kernel state, potentially allowing a local user to gain privileged access or cause a denial of service on the system.
Subscribe to Daily Vulnerability Briefings & KEV Alerts
Concise morning briefings for SecOps, DevSecOps, and SRE teams covering newly exploited CVEs and mitigation priorities.