CVE-2022-49641 addresses a concurrency vulnerability within the Linux kernel's sysctl interface, specifically in the proc_douintvec() function. This function handles reading and writing of sysctl variables, which are kernel parameters accessible at runtime. The vulnerability arises from data races when multiple threads concurrently access and modify a sysctl variable without proper synchronization. Such data races can lead to inconsistent or corrupted data reads and writes, potentially causing unpredictable kernel behavior or system instability. The patch introduces the use of READ_ONCE() and WRITE_ONCE() macros to ensure atomic access to the sysctl variables, preventing load/store tearing and eliminating the data race condition. While proc_douintvec() itself is somewhat tolerant to data races, the fix is necessary to maintain data integrity and avoid subtle bugs in subsystems interacting with sysctl. This vulnerability is present in multiple Linux kernel versions identified by specific commit hashes and was publicly disclosed on February 26, 2025. There are currently no known exploits in the wild targeting this issue, and no CVSS score has been assigned yet.

For European organizations relying on Linux-based systems—ranging from servers, embedded devices, to cloud infrastructure—this vulnerability could lead to kernel instability or unpredictable behavior due to race conditions in sysctl parameter handling. Although it does not directly enable privilege escalation or remote code execution, the data race could cause system crashes or corruption of kernel parameters, potentially disrupting critical services. Systems with high concurrency or heavy sysctl usage may be more susceptible to triggering this issue. Given Linux's widespread adoption across European enterprises, government agencies, and critical infrastructure, unpatched systems could experience degraded reliability or availability. However, the absence of known exploits and the nature of the vulnerability suggest a lower immediate risk of targeted attacks. Nonetheless, the vulnerability could be leveraged as part of a complex attack chain or to cause denial-of-service conditions in sensitive environments.

European organizations should prioritize applying the official Linux kernel patches that implement READ_ONCE() and WRITE_ONCE() protections in proc_douintvec(). System administrators must track kernel updates from their Linux distribution vendors and deploy them promptly. For environments where immediate patching is challenging, organizations should audit sysctl usage patterns and reduce concurrent modifications to sysctl variables where possible. Employing kernel hardening techniques and monitoring kernel logs for anomalies related to sysctl operations can help detect potential exploitation attempts or instability. Additionally, testing kernel updates in staging environments before production deployment is advised to ensure compatibility and stability. Organizations should also maintain robust backup and recovery procedures to mitigate potential service disruptions caused by kernel instability.