CVE-2022-50761 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
x86/xen: Fix memory leak in xen_init_lock_cpu()
In xen_init_lock_cpu(), the @name has allocated new string by kasprintf(), if bind_ipi_to_irqhandler() fails, it should be freed, otherwise may lead to a memory leak issue, fix it.
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Analysis
by VulDB Data Team • 04/21/2026
The vulnerability identified as CVE-2022-50761 represents a memory leak issue within the Linux kernel's x86/xen subsystem that specifically affects systems utilizing Xen hypervisor virtualization. This flaw exists in the xen_init_lock_cpu() function where dynamic memory allocation occurs through the kasprintf() function to create a string name for interrupt handling. The vulnerability stems from improper error handling logic that fails to release the allocated memory when the subsequent bind_ipi_to_irqhandler() function call encounters an error condition. This memory leak scenario demonstrates a classic pattern of resource management failure where allocated kernel memory remains unreleased, potentially leading to gradual memory exhaustion over time.
The technical implementation of this vulnerability occurs within the x86 architecture's Xen hypervisor integration code where the kernel attempts to establish interrupt handling for CPU locking operations. When xen_init_lock_cpu() executes, it first allocates memory for a string name using kasprintf() which dynamically allocates kernel memory from the kernel's heap. The function then attempts to bind an inter-processor interrupt to an IRQ handler through bind_ipi_to_irqhandler() which may fail due to various conditions such as resource exhaustion, invalid parameters, or system constraints. The critical flaw lies in the absence of proper cleanup code that would free the previously allocated memory when the bind operation fails, creating a memory leak that accumulates with each failed execution attempt.
From an operational impact perspective, this vulnerability presents a moderate security risk that primarily affects systems running Linux kernel versions with Xen virtualization support. The memory leak gradually consumes available kernel heap memory, potentially leading to system instability, performance degradation, or in extreme cases, system crashes or denial of service conditions. While the immediate security implications may not be severe, the cumulative effect of leaked memory can impact system reliability over extended periods of operation, particularly in high-availability environments or systems with frequent virtualization operations. The vulnerability affects the kernel's memory management subsystem and could potentially impact other kernel components that depend on sufficient available memory for proper operation.
The mitigation strategy for CVE-2022-50761 involves applying the official kernel patch that ensures proper memory cleanup when bind_ipi_to_irqhandler() fails. This fix implements the correct error handling pattern by adding a conditional check to free the allocated memory using kfree() when the interrupt binding operation fails. The solution aligns with standard kernel development practices and security principles outlined in the Common Weakness Enumeration (CWE) category CWE-401, which addresses improper cleanup of memory allocation. Additionally, this vulnerability relates to ATT&CK technique T1068, which involves privilege escalation through exploitation of kernel vulnerabilities, though the specific impact here is more focused on resource exhaustion rather than direct privilege escalation. Organizations should prioritize applying the kernel update containing this fix, particularly in virtualized environments where Xen hypervisor is actively utilized, as the memory leak could compound over time and affect system stability and performance metrics in production environments.