CVE-2022-49700 is a high-severity vulnerability in the Linux kernel's SLUB memory allocator subsystem, specifically within the slab allocator implementation. The flaw arises from missing updates to the Thread ID (TID) during slab deactivation, which leads to race conditions when multiple operations concurrently access the same CPU slab cache. The slab allocator uses per-CPU caches to optimize memory allocation performance, relying on the stability of the slab pointer as long as the TID remains unchanged. However, two code paths in __slab_alloc() fail to update the TID when deactivating the CPU slab, causing inconsistencies in the slab's freelist and inuse counters. This can result in objects being lost or freed onto the wrong slab's freelist, corrupting internal state. The most severe consequence is that the allocator may mistakenly believe a slab is unused and free its backing page while it still contains allocated objects, leading to use-after-free conditions. Exploiting this vulnerability requires local access with limited privileges (PR:L), no user interaction, and low attack complexity. The impact affects confidentiality, integrity, and availability since use-after-free can lead to arbitrary code execution, privilege escalation, or system crashes. The vulnerability affects multiple Linux kernel versions identified by the same commit hash, indicating a widespread issue across kernel builds. Although no known exploits are publicly reported, the technical complexity and potential for severe memory corruption make it a critical concern for Linux systems relying on SLUB allocator. The CVSS 3.1 base score is 7.8 (high), reflecting the significant risk posed by this flaw.

For European organizations, the impact of CVE-2022-49700 is substantial, especially those running Linux-based servers, cloud infrastructure, or embedded systems. The vulnerability can lead to use-after-free conditions, enabling attackers with local access to escalate privileges, execute arbitrary code in kernel context, or cause denial of service via system crashes. This threatens the confidentiality and integrity of sensitive data and the availability of critical services. Industries such as finance, telecommunications, healthcare, and government, which heavily rely on Linux servers and virtualized environments, are at heightened risk. Additionally, organizations using Linux in IoT devices or industrial control systems may face operational disruptions. The complexity of exploitation limits remote attacks, but insider threats or compromised user accounts could leverage this flaw to gain kernel-level control. Given the widespread deployment of Linux across European data centers and enterprises, failure to patch this vulnerability could lead to significant security incidents and regulatory compliance issues under frameworks like GDPR.

Mitigation requires applying the official Linux kernel patches that address the missing TID updates during slab deactivation. Organizations should prioritize updating to the latest kernel versions containing the fix. Beyond patching, system administrators should: 1) Restrict local access to trusted users only, minimizing the risk of exploitation by unprivileged accounts. 2) Employ kernel hardening techniques such as Kernel Page Table Isolation (KPTI), SELinux/AppArmor policies, and seccomp filters to limit the impact of potential kernel exploits. 3) Monitor kernel logs and system behavior for anomalies indicative of memory corruption or use-after-free exploitation attempts. 4) Use runtime security tools capable of detecting unusual slab allocator behavior or memory corruption patterns. 5) In environments where immediate patching is not feasible, consider isolating vulnerable systems or limiting their exposure to untrusted users. 6) Maintain regular backups and incident response plans to quickly recover from potential exploitation. These targeted measures complement patching and reduce the attack surface related to this vulnerability.