CVE-2026-23027 in Linux
Summary
by MITRE • 01/31/2026
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Fix kvm_device leak in kvm_pch_pic_destroy()
In kvm_ioctl_create_device(), kvm_device has allocated memory, kvm_device->destroy() seems to be supposed to free its kvm_device struct, but kvm_pch_pic_destroy() is not currently doing this, that would lead to a memory leak.
So, fix it.
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Analysis
by VulDB Data Team • 02/02/2026
The vulnerability CVE-2026-23027 represents a critical memory management flaw within the Linux kernel's KVM subsystem specifically affecting LoongArch architecture implementations. This issue manifests in the hypervisor's device management functionality where proper resource cleanup mechanisms have been omitted, creating persistent memory leaks that can accumulate over time and potentially impact system stability. The vulnerability occurs within the KVM (Kernel-based Virtual Machine) framework which enables hardware virtualization on Linux systems, particularly affecting systems utilizing LoongArch processors that require specific virtualization support.
The technical flaw resides in the kvm_pch_pic_destroy() function which is responsible for cleaning up peripheral component interconnect pic devices within the KVM virtualization environment. When the kvm_ioctl_create_device() function allocates memory for a kvm_device structure, it expects the corresponding destroy() callback function to properly release all associated resources including the structure itself. However, the kvm_pch_pic_destroy() implementation fails to free the allocated kvm_device struct, resulting in a memory leak where the kernel's memory management system retains references to deallocated structures. This pattern violates fundamental memory management principles and creates a resource exhaustion scenario where repeated device creation and destruction cycles accumulate unreleased memory segments.
The operational impact of this vulnerability extends beyond simple memory consumption as it can lead to progressive system degradation and potential denial of service conditions in virtualized environments. In high-utilization scenarios where virtual machines frequently create and destroy peripheral devices, the accumulated memory leaks can consume significant portions of available system memory, reducing overall system performance and potentially causing system crashes or instability. The vulnerability is particularly concerning in server environments running multiple virtual machines where the cumulative effect of such leaks can severely impact the host system's ability to maintain stable operations. This issue affects the integrity of the kernel's memory management subsystem and can compromise the reliability of virtualized workloads that depend on proper device lifecycle management.
Mitigation strategies for this vulnerability involve implementing proper resource cleanup within the kvm_pch_pic_destroy() function to ensure that all allocated memory structures are properly freed when devices are destroyed. System administrators should prioritize applying the kernel patches that address this specific memory leak issue, as the fix requires modification to the KVM subsystem's device management code to include the missing memory deallocation. The vulnerability aligns with CWE-401 (Improper Release of Memory) and can be categorized under ATT&CK technique T1490 (Inhibit System Recovery) as it can contribute to system instability through resource exhaustion. Organizations should implement regular monitoring of system memory usage in virtualized environments to detect potential memory leak accumulation and ensure that kernel updates are applied promptly to address this and similar vulnerabilities in the KVM subsystem.