CVE-2024-38598 is a vulnerability identified in the Linux kernel's md (multiple device) subsystem, specifically affecting the RAID10 implementation. The issue arises when the bitmap size used for resynchronization is smaller than the array size, which can lead to a kernel soft lockup during certain operations such as lvextend combined with lvchange --syncaction on dm-raid10 devices. The root cause is a logic flaw introduced by commit 301867b1c168, where the function md_bitmap_get_counter() returns early without setting the expected number of blocks to sync, causing the resync loop in md_do_sync() to stall indefinitely. This results in a CPU soft lockup, where the kernel watchdog detects that a CPU is stuck for an extended period (e.g., 26 seconds), effectively halting progress on the resync thread. The vulnerability does not cause data corruption directly but leads to a denial of service (DoS) condition by freezing the RAID resync process. The patch fixes this by ensuring md_bitmap_get_counter() always sets the returned block count, restoring the expected control flow. However, the underlying mismatch between bitmap size and array size remains an unresolved condition that could cause operational issues. This vulnerability affects multiple Linux kernel versions prior to the fix and is particularly relevant for systems using software RAID10 with device mapper logical volumes. No known exploits are reported in the wild as of the publication date.

For European organizations, the impact of CVE-2024-38598 primarily manifests as a denial of service on systems utilizing Linux software RAID10 configurations with device mapper logical volumes. This can disrupt critical storage operations, especially in environments relying on RAID10 for redundancy and performance, such as data centers, cloud providers, and enterprises with on-premises Linux infrastructure. The soft lockup can cause prolonged unavailability of storage arrays, potentially leading to application downtime, delayed backups, or interrupted data synchronization. While no direct data corruption or privilege escalation is indicated, the operational disruption can affect business continuity and service level agreements. Organizations with high reliance on Linux-based storage solutions in sectors like finance, telecommunications, healthcare, and government could experience significant operational risk. The vulnerability's impact is heightened in environments where automated resyncs or volume extensions are routine, as these operations might trigger the lockup. Given the kernel-level nature of the issue, recovery typically requires a system reboot or manual intervention, which may not be feasible in high-availability setups without planned maintenance windows.

To mitigate CVE-2024-38598, European organizations should: 1) Apply the official Linux kernel patches that address the md_bitmap_get_counter() logic to ensure the soft lockup condition is resolved. 2) Audit and verify the consistency between bitmap sizes and array sizes in RAID10 configurations to prevent triggering the underlying mismatch condition. 3) Avoid performing lvextend and lvchange --syncaction operations concurrently on dm-raid10 devices until patches are applied. 4) Implement monitoring for kernel soft lockups and RAID resync progress to detect early signs of this issue. 5) For critical systems, consider temporarily migrating to alternative RAID configurations or hardware RAID solutions until the kernel is updated. 6) Maintain up-to-date backups and test recovery procedures to minimize downtime in case of forced reboots. 7) Engage with Linux distribution vendors for timely updates and backported patches, especially for long-term support kernels. 8) Document and train system administrators on this vulnerability to ensure awareness during storage maintenance operations.