CVE-2024-57793 is a vulnerability identified in the Linux kernel, specifically affecting the handling of memory decryption in virtualized environments using Intel Trust Domain Extensions (TDX) guest virtual machines. The vulnerability arises when the function set_memory_decrypted() fails during operation in CoCo VMs (Confidential Computing VMs). In these scenarios, an untrusted host can induce a failure in set_memory_decrypted(), causing the kernel to leak decrypted memory. This occurs because callers of set_memory_decrypted() may not properly handle error returns, leading to decrypted memory being erroneously shared back to the page allocator. The consequence is that sensitive decrypted memory contents could be exposed or leaked, potentially compromising confidentiality. The patch resolves this by ensuring that decrypted memory is leaked intentionally on failure to prevent silent exposure and removing redundant error prints, as set_memory_decrypted() already triggers a WARN_ONCE() warning. This vulnerability is rooted in the interaction between the Linux kernel's memory management and the TDX guest environment, highlighting risks in confidential computing where memory encryption and isolation are critical. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

For European organizations, this vulnerability poses a significant risk to any infrastructure leveraging Linux-based virtual machines with Intel TDX technology, particularly in confidential computing deployments. Organizations using cloud services or private data centers that implement CoCo VMs for sensitive workloads could face data confidentiality breaches if an attacker controlling the host environment exploits this flaw. The leak of decrypted memory could expose sensitive data such as cryptographic keys, personal data, or intellectual property. This undermines the trust model of confidential computing, which is increasingly adopted in Europe for compliance with stringent data protection regulations like GDPR. Additionally, the vulnerability could lead to functional instability in virtualized environments, impacting availability and integrity of services. Although exploitation requires control or influence over the host, this is a realistic threat in multi-tenant cloud environments or compromised hypervisors. The absence of known exploits suggests limited immediate risk, but the potential impact on confidentiality and trust in virtualization security is high.

European organizations should prioritize updating their Linux kernel versions to the patched releases that address CVE-2024-57793 as soon as they become available. Specifically, kernel maintainers and vendors should ensure that set_memory_decrypted() error handling is correctly implemented to prevent decrypted memory leaks. Organizations running confidential computing workloads on Intel TDX-enabled VMs must audit their virtualization stack and host security to minimize the risk of host compromise. Employing strict host isolation, monitoring for unusual host behavior, and limiting administrative access can reduce exploitation likelihood. Additionally, organizations should review their memory encryption configurations and consider implementing runtime memory integrity checks or additional encryption layers at the application level. Cloud service providers should communicate patch availability and encourage customers to update promptly. Finally, organizations should conduct threat modeling and penetration testing focused on confidential computing environments to detect potential exploitation attempts.