CVE-2022-0516 in Linux
Summary
by MITRE • 03/10/2022
A vulnerability was found in kvm_s390_guest_sida_op in the arch/s390/kvm/kvm-s390.c function in KVM for s390 in the Linux kernel. This flaw allows a local attacker with a normal user privilege to obtain unauthorized memory write access. This flaw affects Linux kernel versions prior to 5.17-rc4.
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Analysis
by VulDB Data Team • 05/18/2025
The vulnerability identified as CVE-2022-0516 resides within the Linux kernel's KVM implementation for s390 architecture, specifically in the kvm_s390_guest_sida_op function located in arch/s390/kvm/kvm-s390.c. This flaw represents a critical security issue that undermines the integrity of the virtualization layer on IBM System/390 mainframe systems. The vulnerability manifests as an improper validation mechanism that fails to properly sanitize memory access operations, creating a pathway for privilege escalation. The affected component operates within the kernel's virtual machine monitor subsystem, which is responsible for managing virtual machine instances and their interactions with the underlying hardware resources. This particular implementation flaw exists in the s390 guest SIDA (System Information Data Area) operations handling, which is essential for managing system information and communication between virtual machines and the hypervisor.
The technical nature of this vulnerability stems from insufficient bounds checking and memory validation within the KVM subsystem's s390 implementation. When a guest operating system attempts to perform SIDA operations, the kernel fails to properly validate the memory addresses and access permissions, allowing an attacker to manipulate memory locations that should remain protected. This memory write access occurs through a controlled interface that normally should only permit legitimate operations, but due to the flawed validation logic, malicious input can bypass these security checks. The vulnerability essentially creates a write-what-where primitive that can be exploited to overwrite arbitrary memory locations, potentially leading to complete system compromise. This type of flaw falls under the CWE-121 category of stack-based buffer overflow, though it manifests as a memory corruption issue rather than a traditional buffer overflow. The vulnerability affects systems running Linux kernel versions prior to 5.17-rc4, indicating that the fix was implemented in the kernel development cycle but not yet widely deployed in production environments.
The operational impact of CVE-2022-0516 extends beyond simple privilege escalation, as it provides a local attacker with the capability to manipulate critical kernel memory structures. An attacker with normal user privileges can leverage this vulnerability to execute arbitrary code with kernel-level privileges, effectively bypassing the security model that separates user applications from the kernel. This could result in complete system compromise, data exfiltration, and the ability to maintain persistent access to the affected systems. The attack vector is particularly concerning because it requires only local user access, making it exploitable in environments where user accounts are shared or where attackers have legitimate access to system resources. The vulnerability affects virtualized environments running on IBM s390 systems, which are commonly used in enterprise data centers and mainframe computing environments where security is paramount. The impact is amplified in scenarios where multiple virtual machines share the same physical host, as exploitation could potentially affect other VMs running on the same system.
Mitigation strategies for CVE-2022-0516 should prioritize immediate kernel updates to versions 5.17-rc4 or later, which contain the necessary patches to address the memory validation issues. Organizations should implement comprehensive monitoring to detect any suspicious memory access patterns or unauthorized system modifications that might indicate exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date kernel versions, particularly in virtualized environments where the attack surface is already expanded. Security teams should conduct thorough assessments of their s390-based virtualization environments to identify systems running vulnerable kernel versions. Additionally, implementing runtime protection mechanisms such as kernel address space layout randomization and stack canaries can provide additional layers of defense. The ATT&CK framework categorizes this vulnerability under T1068 for exploit for privilege escalation, with potential techniques involving memory corruption and kernel exploitation. Organizations should also consider implementing network segmentation and access controls to limit local user access where possible, reducing the attack surface for potential exploitation. Regular security audits and vulnerability assessments should be conducted to ensure that all systems running KVM on s390 architecture remain protected against similar vulnerabilities.