CVE-2024-42250 is a vulnerability identified in the Linux kernel's cachefiles subsystem. The issue arises due to missing lock protection in the poll routine when iterating over an xarray data structure. Specifically, while the Read-Copy-Update (RCU) read lock ensures that the slot of the radix tree is pinned and stable, it does not guarantee the safety of the data structure stored within that slot, such as the struct cachefiles_req. The poll routine dereferences these structures without adequate locking, which can lead to unsafe memory access. The root cause is that the RCU read lock alone is insufficient for protecting the iteration over the radix tree elements in this context, and a spinlock is necessary to prevent concurrent modifications that could cause data races or memory corruption. This vulnerability could potentially lead to undefined behavior such as kernel crashes, data corruption, or privilege escalation if exploited. However, there are no known exploits in the wild at the time of publication. The affected versions are specific Linux kernel commits identified by their hashes, indicating that this is a recent and targeted fix. The vulnerability was reserved on July 30, 2024, and published on August 7, 2024. No CVSS score has been assigned yet, and no patch links were provided in the source data, but the fix involves adding the missing spinlock protection in the poll routine to ensure safe iteration over the radix tree elements.

For European organizations, the impact of CVE-2024-42250 depends largely on their use of Linux systems that incorporate the affected cachefiles subsystem versions. The cachefiles module is typically used to cache network filesystems locally, improving performance in environments using NFS or similar protocols. If exploited, this vulnerability could cause kernel instability or crashes, potentially leading to denial of service conditions. In more severe cases, if an attacker can leverage this flaw to corrupt kernel memory or escalate privileges, it could compromise the confidentiality and integrity of sensitive data and systems. This is particularly critical for organizations relying on Linux servers for critical infrastructure, cloud services, or data centers. Given the kernel-level nature of the vulnerability, successful exploitation could allow attackers to bypass security controls, disrupt services, or gain unauthorized access. Although no active exploits are known, the vulnerability's presence in the kernel means that any Linux-based system using the affected versions is at risk until patched. European organizations in sectors such as finance, telecommunications, government, and critical infrastructure should prioritize addressing this issue to maintain system stability and security.

To mitigate CVE-2024-42250, European organizations should: 1) Identify Linux systems running affected kernel versions by checking kernel commit hashes or version numbers corresponding to the vulnerable code. 2) Apply the official Linux kernel patches that add the missing spinlock protection in the cachefiles poll routine as soon as they become available from trusted sources such as the Linux kernel mailing list or distribution vendors. 3) If immediate patching is not possible, consider disabling the cachefiles module temporarily to prevent exploitation, especially on systems exposed to untrusted networks. 4) Implement strict access controls and monitoring on systems using cachefiles to detect unusual kernel behavior or crashes that might indicate exploitation attempts. 5) Maintain up-to-date backups and recovery plans to minimize downtime in case of kernel crashes or attacks. 6) Coordinate with Linux distribution vendors for timely updates and advisories, and test patches in staging environments before deployment to production. 7) Educate system administrators about the importance of kernel security and the risks associated with kernel-level vulnerabilities to ensure rapid response.