CVE-2022-50667 in Linux
Summary
by MITRE • 12/09/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Fix memory leak in vmw_mksstat_add_ioctl()
If the copy of the description string from userspace fails, then the page for the instance descriptor doesn't get freed before returning -EFAULT, which leads to a memleak.
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Analysis
by VulDB Data Team • 03/29/2026
The vulnerability identified as CVE-2022-50667 resides within the Linux kernel's graphics subsystem, specifically affecting the vmwgfx driver used for VMware graphics hardware. This flaw manifests as a memory leak in the drm/vmwgfx component when handling the vmw_mksstat_add_ioctl() function, which is responsible for managing instance descriptors in the virtualized graphics environment. The issue occurs during the processing of user-space requests where the kernel attempts to copy descriptive strings from user space into kernel memory, creating a scenario where memory allocation failures are not properly handled. The vulnerability represents a classic resource management error that can accumulate over time, potentially leading to system instability or performance degradation in environments heavily utilizing virtualized graphics capabilities.
The technical implementation of this vulnerability stems from inadequate error handling within the kernel's memory management routines. When the copy_from_user() operation fails during the string duplication process, the kernel code fails to properly release the allocated page memory that was previously allocated for the instance descriptor structure. This memory leak occurs because the cleanup path is bypassed when the error condition is detected, leaving the allocated memory in an unreleased state. The function returns -EFAULT to indicate the failure, but the associated memory management cleanup does not execute, creating a persistent memory leak that can grow with repeated calls to the affected ioctl interface. This type of vulnerability falls under the category of improper resource handling as defined by CWE-404, specifically related to memory leaks in kernel space operations.
The operational impact of this vulnerability extends beyond simple memory consumption, as it can affect system stability and performance in virtualized environments where the VMware graphics driver is actively used. In high-frequency usage scenarios or long-running systems, the accumulated memory leak can lead to progressive memory exhaustion, potentially causing system slowdowns, application crashes, or even complete system instability. The vulnerability is particularly concerning in server environments or cloud infrastructure where virtual machines with graphics capabilities are prevalent, as it can compound over time and affect multiple concurrent users or virtual instances. Attackers who can repeatedly trigger this ioctl call could potentially accelerate memory exhaustion, though the vulnerability itself does not provide direct execution capabilities.
Mitigation strategies for CVE-2022-50667 involve applying the kernel patch that implements proper error handling for the memory allocation failure case, ensuring that all allocated resources are properly freed regardless of the success or failure of the string copy operation. System administrators should prioritize updating their Linux kernel versions to include the fix provided by the upstream kernel maintainers, particularly in production environments where VMware virtual graphics is utilized. Monitoring for memory consumption patterns and implementing automated alerting for unusual memory usage trends can help detect potential exploitation of this vulnerability. The fix aligns with best practices for kernel development and follows the ATT&CK framework's approach to mitigating kernel-level vulnerabilities by ensuring proper resource management and error handling in system calls. Organizations should also consider implementing kernel hardening measures and access controls to limit exposure of the affected ioctl interface to trusted processes only.