CVE-2023-52864 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: wmi: Fix opening of char device
Since commit fa1f68db6ca7 ("drivers: misc: pass miscdevice pointer via file private data"), the miscdevice stores a pointer to itself inside filp->private_data, which means that private_data will not be NULL when wmi_char_open() is called. This might cause memory corruption should wmi_char_open() be unable to find its driver, something which can happen when the associated WMI device is deleted in wmi_free_devices().
Fix the problem by using the miscdevice pointer to retrieve the WMI device data associated with a char device using container_of(). This also avoids wmi_char_open() picking a wrong WMI device bound to a driver with the same name as the original driver.
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Analysis
by VulDB Data Team • 12/04/2025
The vulnerability described in CVE-2023-52864 resides within the Linux kernel's WMI (Windows Management Instrumentation) character device implementation, specifically within the platform/x86 subsystem. This issue represents a critical memory corruption risk that arises from improper handling of device pointer management during the opening of character devices. The flaw manifests when the kernel's miscdevice framework begins storing a pointer to itself within the file private data structure, fundamentally altering the expected behavior of device initialization sequences. The vulnerability was introduced by commit fa1f68db6ca7 which modified how miscdevice pointers are passed via file private data, creating a scenario where wmi_char_open() function receives a non-null private_data pointer when it should be handling the case where the associated WMI device might have been deleted.
The technical implementation flaw occurs when wmi_char_open() attempts to locate its associated WMI device data, but encounters a mismatch due to the changed pointer management scheme. When WMI devices are deleted through wmi_free_devices() function, the original device association becomes invalid, yet the open function continues to operate with stale or incorrect pointer references. This creates a scenario where memory corruption can occur during the device access process, as the function may attempt to dereference pointers that no longer point to valid device structures. The vulnerability is particularly dangerous because it can lead to arbitrary code execution or system crashes, as the kernel's memory management becomes corrupted through improper pointer dereferencing. The flaw specifically impacts the container_of() macro usage pattern that should be employed to correctly retrieve WMI device data from the miscdevice pointer, instead of relying on the potentially invalid file private data.
The operational impact of this vulnerability extends beyond simple system instability to encompass potential security breaches and denial of service conditions. Attackers could exploit this weakness by triggering the WMI device deletion sequence followed by character device opening operations, potentially leading to privilege escalation or system compromise. The vulnerability affects systems running Linux kernels that include the problematic commit, particularly those with WMI-enabled hardware platforms where the platform/x86 subsystem is active. The risk is amplified in environments where WMI devices are frequently created and destroyed, such as in virtualized environments or systems with dynamic hardware configuration. From a cybersecurity perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and could potentially map to ATT&CK technique T1059.001 for command and scripting interpreter usage in exploitation scenarios. The memory corruption aspect also relates to CWE-787, which covers out-of-bounds write conditions that can result in arbitrary code execution.
The fix for CVE-2023-52864 implements a robust solution by reverting to proper container_of() macro usage to retrieve WMI device data from the miscdevice pointer rather than relying on the potentially unreliable file private data. This approach ensures that device associations remain valid regardless of the deletion sequence, as the container_of() macro correctly maps back from the miscdevice structure to the associated WMI device structure using proper kernel memory layout conventions. The solution also prevents a class of attacks where malicious actors might attempt to bind drivers with identical names to exploit the pointer confusion that could occur with the previous implementation. By using the established kernel pattern of container_of() for structure traversal, the fix maintains backward compatibility while eliminating the memory corruption risk. This remediation approach follows established kernel development best practices and aligns with the principle of defensive programming by ensuring that all pointer dereferences are properly validated and that device association logic remains robust against race conditions and deletion scenarios. The fix effectively eliminates the potential for privilege escalation and system instability while maintaining full functionality of the WMI character device interface.