CVE-2024-56742 is a vulnerability identified in the Linux kernel, specifically within the vfio/mlx5 driver component. The issue relates to an unwind problem in the function mlx5vf_add_migration_pages(). This function is responsible for adding pages to a scatter-gather (SG) table during device memory migration operations. The vulnerability arises when a set of pages is allocated but fails to be added to the SG table. In such cases, the allocated pages are not properly freed, leading to a memory leak. The fix ensures that any pages allocated but not successfully added to the SG table are freed to prevent resource leakage. Pages that are successfully added are freed later by mlx5vf_free_data_buffer(). This vulnerability is categorized under CWE-401 (Improper Release of Memory Before Removing Last Reference or Pointer), indicating a memory management flaw. The CVSS v3.1 score is 3.3, reflecting a low severity level. The attack vector is local (AV:L), requiring low attack complexity (AC:L) and low privileges (PR:L), with no user interaction (UI:N). The impact affects availability only (A:L), with no confidentiality or integrity impact. No known exploits are reported in the wild at this time. The affected Linux kernel versions are identified by specific commit hashes, indicating the vulnerability is present in certain recent kernel builds prior to the fix. This issue is primarily a resource management flaw that could lead to gradual memory exhaustion if exploited repeatedly, potentially degrading system performance or causing denial of service due to resource depletion.

For European organizations, the impact of CVE-2024-56742 is generally low but should not be dismissed. Since the vulnerability causes a memory leak in the Linux kernel's vfio/mlx5 driver, systems using this driver—commonly associated with Mellanox network devices—may experience degraded performance or instability over time under certain workloads. Organizations relying on high-performance computing, data centers, or network-intensive applications that utilize Mellanox hardware and Linux vfio drivers could see service interruptions if the leak accumulates. While the vulnerability does not directly compromise confidentiality or integrity, availability degradation can impact critical services, especially in sectors like finance, telecommunications, and cloud providers prevalent in Europe. The requirement for local access and low privileges limits remote exploitation, reducing the risk of widespread attacks. However, insider threats or compromised local accounts could trigger the issue. Given the widespread use of Linux in European infrastructure, particularly in enterprise and cloud environments, timely patching is important to maintain system reliability and prevent potential denial of service conditions caused by resource exhaustion.

To mitigate CVE-2024-56742, European organizations should: 1) Identify and inventory systems running affected Linux kernel versions that include the vulnerable vfio/mlx5 driver, focusing on those using Mellanox network devices or related hardware. 2) Apply the official Linux kernel patches or upgrade to a kernel version that includes the fix for this vulnerability as soon as possible. 3) Monitor system memory usage and kernel logs for signs of memory leaks or instability related to vfio/mlx5 operations. 4) Limit local access to trusted users only, enforcing strict access controls and privilege management to reduce the risk of exploitation by low-privilege users. 5) For environments where patching is delayed, consider temporarily disabling or unloading the vfio/mlx5 driver if feasible, or restricting workloads that trigger migration page additions. 6) Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid detection and remediation. 7) Engage with hardware vendors for firmware and driver updates that complement kernel patches to ensure comprehensive protection.