CVE-2022-50337 in Linux
Summary
by MITRE • 09/15/2025
In the Linux kernel, the following vulnerability has been resolved:
ocxl: fix pci device refcount leak when calling get_function_0()
get_function_0() calls pci_get_domain_bus_and_slot(), as comment says, it returns a pci device with refcount increment, so after using it, pci_dev_put() needs be called.
Get the device reference when get_function_0() is not called, so pci_dev_put() can be called in the error path and callers unconditionally. And add comment above get_dvsec_vendor0() to tell callers to call pci_dev_put().
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Analysis
by VulDB Data Team • 01/10/2026
The vulnerability identified as CVE-2022-50337 resides within the Linux kernel's OpenCAPI PCIe (ocxl) subsystem, representing a critical resource management flaw that could lead to system instability and potential denial of service conditions. This issue specifically affects the handling of PCI device reference counting during the execution of the get_function_0() function, which is part of the OpenCAPI PCIe driver implementation. The root cause stems from improper management of reference counts for PCI devices, creating a scenario where device references are not properly released, leading to resource leaks that can accumulate over time and eventually exhaust available system resources.
The technical flaw manifests when the get_function_0() function invokes pci_get_domain_bus_and_slot() to retrieve a PCI device structure, which according to kernel documentation and best practices, increments the reference count of the returned device. However, the original implementation failed to properly release this reference in all execution paths, particularly during error conditions where the function might exit prematurely without calling pci_dev_put(). This creates a memory leak scenario where the PCI device reference remains in memory even though it's no longer needed, as the reference count never reaches zero. The vulnerability is categorized under CWE-404, which specifically addresses improper resource management and resource leaks, and aligns with ATT&CK technique T1490, representing resource exhaustion attacks that can be facilitated by improper reference counting mechanisms.
The operational impact of this vulnerability extends beyond simple memory consumption, potentially affecting system stability and performance across environments utilizing OpenCAPI PCIe hardware. When multiple instances of the problematic code path are executed, the cumulative effect of unreleased references can lead to system resource exhaustion, particularly in high-throughput scenarios where the OpenCAPI driver is actively managing multiple PCIe functions. The vulnerability affects systems running Linux kernels with OpenCAPI PCIe support, potentially impacting servers, workstations, and embedded systems that utilize this specific PCIe subsystem. Attackers could exploit this weakness to perform resource exhaustion attacks, leading to system crashes, reduced performance, or complete system unavailability, while the underlying reference counting mechanism fails to properly manage device lifecycle management.
Mitigation strategies for CVE-2022-50337 involve implementing proper reference counting practices throughout the affected code paths, ensuring that all PCI device references obtained through pci_get_domain_bus_and_slot() are properly released using pci_dev_put() regardless of execution flow. The fix requires modifying the get_function_0() implementation to acquire the device reference early in the function execution and subsequently release it in all possible code paths, including error conditions, thereby ensuring proper resource cleanup. Additionally, developers should enhance code documentation by adding clear comments above get_dvsec_vendor0() to explicitly instruct callers about the need to invoke pci_dev_put() after using the returned device reference. This remediation approach aligns with kernel security best practices and addresses the fundamental issue of improper resource management while maintaining the intended functionality of the OpenCAPI PCIe driver. System administrators should prioritize applying kernel updates that include this fix, particularly in production environments where OpenCAPI PCIe hardware is deployed, as the vulnerability represents a potential vector for denial of service attacks that could compromise system availability and stability.