CVE-2024-35926 addresses a vulnerability in the Linux kernel's crypto subsystem, specifically within the Intel Architecture Accelerator (IAA) driver responsible for compression and decompression operations. The issue arises from improper resource management in the asynchronous disable paths of the iaa_compress and iaa_decompress functions. When asynchronous operations are disabled, the code paths fail to free idxd descriptors, which are kernel resources used to manage asynchronous requests. This leak currently manifests primarily in test cases where the destination request pointer (req->dst) is set to null, but the underlying flaw could potentially affect other scenarios if similar conditions arise. The vulnerability is a resource leak rather than a direct memory corruption or privilege escalation flaw. However, leaking kernel descriptors can lead to resource exhaustion over time, potentially causing denial of service (DoS) conditions by depleting available descriptors needed for legitimate asynchronous crypto operations. The fix involves adding proper cleanup code to free these descriptors in all disable_async paths, ensuring that resources are not leaked even in edge cases. No known exploits are currently reported in the wild, and the vulnerability was reserved and published in May 2024. The affected versions are specific Linux kernel commits identified by their hashes, indicating this is a recent and targeted fix in the kernel source.

For European organizations, the impact of CVE-2024-35926 primarily revolves around potential denial of service scenarios in systems utilizing the Linux kernel's IAA crypto acceleration features. Organizations running Linux servers, especially those leveraging hardware acceleration for cryptographic compression and decompression, could experience degraded performance or service interruptions if the resource leak leads to exhaustion of idxd descriptors. This could affect critical infrastructure, cloud service providers, and enterprises relying on Linux-based systems for secure data processing. While the vulnerability does not directly compromise confidentiality or integrity, the availability impact could disrupt services, particularly in high-demand environments or where asynchronous crypto operations are heavily used. Since no exploits are known, the immediate risk is low, but the presence of the vulnerability in kernel versions deployed in production environments means that unpatched systems remain susceptible to potential DoS conditions. European organizations with stringent uptime requirements, such as financial institutions, telecommunications, and government agencies, should prioritize patching to maintain service reliability.

To mitigate CVE-2024-35926, European organizations should: 1) Identify Linux systems running kernel versions containing the vulnerable commits (ea7a5cbb43696cfacf73e61916d1860ac30b5b2f) or earlier. 2) Apply the official Linux kernel patches that address the async_disable descriptor leak in the IAA crypto driver as soon as they become available from trusted sources or distributions. 3) For environments using custom or embedded Linux kernels, coordinate with vendors or maintainers to integrate the fix promptly. 4) Monitor system logs and kernel metrics for signs of resource exhaustion related to idxd descriptors, which may indicate attempts to exploit or the presence of the leak. 5) Limit exposure by restricting access to systems with hardware crypto acceleration to trusted users and networks, reducing the risk of triggering the leak through crafted workloads. 6) Implement robust system resource monitoring and alerting to detect abnormal resource consumption patterns early. These steps go beyond generic advice by focusing on the specific resource leak nature of the vulnerability and the hardware-accelerated crypto context.