CVE-2024-50265 is a vulnerability identified in the Linux kernel's OCFS2 (Oracle Cluster File System version 2) filesystem driver. The flaw arises from improper handling of entry removal in the ocfs2_xa_remove() function, which leads to a null pointer dereference. Specifically, the issue occurs when the ocfs2_xa_cleanup_value_truncate() function attempts to truncate extended attribute (xattr) data and remove an entry. Due to a logic error, the same entry is removed twice: once inside ocfs2_xa_cleanup_value_truncate() and again upon returning to ocfs2_xa_remove(), causing a null pointer dereference and kernel crash. This bug was reproducible using Syzkaller, a kernel fuzzing tool, which triggered the fault by injecting a failure (-ENOMEM) in the ocfs2_xa_value_truncate() call. The root cause is an incorrect return code check that fails to skip the second removal of the same entry. The fix involves adjusting the control flow to prevent the duplicate removal, thereby avoiding the null pointer dereference. This vulnerability affects Linux kernel versions identified by the commit hash 399ff3a748cf4c8c853e96dd477153202636527b and potentially other versions containing the same flawed code. While no CVSS score has been assigned yet, the vulnerability can cause a denial of service (DoS) by crashing the kernel, impacting system availability. There is no indication of privilege escalation or remote code execution, and exploitation requires triggering specific filesystem operations on OCFS2 volumes. No known exploits are currently reported in the wild.

For European organizations, the primary impact of CVE-2024-50265 is a potential denial of service condition on Linux systems using the OCFS2 filesystem. OCFS2 is typically used in clustered or shared storage environments, often in enterprise or data center contexts. A successful exploitation could cause kernel panics leading to system crashes and downtime, disrupting critical services and applications relying on affected servers. This could affect cloud providers, hosting services, and enterprises running clustered Linux environments with OCFS2. Although the vulnerability does not appear to allow privilege escalation or data corruption directly, repeated crashes could degrade service availability and reliability. Organizations with high availability requirements or those using OCFS2 for shared storage in clustered environments should be particularly cautious. The lack of known exploits reduces immediate risk, but the vulnerability's presence in the Linux kernel means it could be targeted once public details are widely known. The impact on confidentiality and integrity is minimal, but availability impact is significant in affected environments.

1. Apply the official Linux kernel patch that fixes the ocfs2_xa_remove() logic to prevent double removal of entries and null pointer dereference. Monitor Linux kernel mailing lists and vendor advisories for updated kernel releases addressing CVE-2024-50265. 2. If immediate patching is not possible, consider disabling or avoiding the use of OCFS2 filesystems until a fix is applied, especially in production or critical environments. 3. Implement robust monitoring of kernel logs and system stability to detect early signs of kernel panics or crashes related to OCFS2 operations. 4. Limit access to systems with OCFS2 volumes to trusted users and processes to reduce the risk of triggering the vulnerability unintentionally or maliciously. 5. For clustered environments, ensure failover and redundancy mechanisms are tested and operational to minimize downtime in case of crashes. 6. Engage with Linux distribution vendors for backported patches if using long-term support kernels. 7. Conduct thorough testing of updated kernels in staging environments before deployment to production to avoid regressions.