CVE-2024-53155 is a vulnerability identified in the Linux kernel's OCFS2 (Oracle Cluster File System version 2) filesystem driver, specifically within the ocfs2_file_read_iter() function. The issue arises from the use of an uninitialized value in the 'private' field of the 'struct kiocb' passed from the block layer. This uninitialized value can lead to undefined behavior during file read and write operations handled by ocfs2_file_read_iter() and ocfs2_file_write_iter(). The vulnerability was detected by Syzbot through a Kernel Memory Sanitizer (KMSAN) report indicating an uninitialized value usage, which is a serious concern as it can cause kernel crashes or data corruption. The root cause is that the 'private' field in the kiocb structure was not properly initialized before use. The fix involves introducing a new initialization function, ocfs2_iocb_init_rw_locked(), which ensures the 'private' field is correctly set before being used in the I/O completion routines such as ocfs2_dio_end_io(). This patch prevents the propagation of uninitialized memory usage in the OCFS2 file operations. Since OCFS2 is a cluster filesystem used primarily in environments requiring shared storage access, such as clustered databases or high-availability systems, this vulnerability could affect systems relying on OCFS2 for critical data storage. The vulnerability affects specific Linux kernel versions identified by commit hashes, indicating it is present in recent kernel builds prior to the patch. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. However, the vulnerability's nature suggests potential risks related to system stability and data integrity in affected environments.

For European organizations, especially those operating data centers, cloud infrastructure, or high-availability clusters using Linux with OCFS2, this vulnerability could lead to kernel crashes or data corruption during file read/write operations. This can result in service disruptions, loss of data integrity, and potential downtime impacting business continuity. Organizations relying on OCFS2 for clustered storage in sectors such as finance, telecommunications, healthcare, and critical infrastructure may face operational risks. Although no active exploits are known, the presence of uninitialized memory usage in kernel code can be a vector for more sophisticated attacks, including privilege escalation or denial of service, if combined with other vulnerabilities. The impact is heightened in environments where OCFS2 is used extensively for shared storage, as corrupted or unstable file operations could cascade across cluster nodes. Given the Linux kernel's widespread use in European enterprise and public sector environments, the vulnerability's reach is significant, particularly in organizations with complex storage architectures.

European organizations should prioritize applying the official Linux kernel patches that introduce ocfs2_iocb_init_rw_locked() to properly initialize the kiocb 'private' field. Systems using OCFS2 should be audited to confirm kernel versions and patch status. Where immediate patching is not feasible, organizations should consider temporarily disabling OCFS2 usage or migrating critical workloads to alternative, unaffected filesystems. Monitoring kernel logs for unusual I/O errors or crashes related to OCFS2 can provide early detection of exploitation attempts or instability. Additionally, organizations should implement strict access controls and kernel hardening measures to reduce the attack surface. Regular kernel updates and integration of memory sanitizer tools in testing environments can help detect similar issues proactively. Backup and disaster recovery plans should be validated to mitigate potential data corruption impacts. Collaboration with Linux distribution vendors for timely patch deployment and verification is also recommended.