CVE-2022-49233 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Call dc_stream_release for remove link enc assignment
[Why]
A porting error resulted in the stream assignment for the link being retained without being released - a memory leak.
[How]
Fix the porting error by adding back the dc_stream_release() intended as part of the original patch.
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Analysis
by VulDB Data Team • 03/19/2025
The vulnerability identified as CVE-2022-49233 represents a memory leak within the Linux kernel's display subsystem, specifically affecting the AMD display driver component. This issue manifests in the direct rendering manager (drm) framework where the display controller fails to properly release memory resources associated with stream assignments during link removal operations. The flaw stems from a porting error that occurred during kernel development, where critical cleanup functionality was inadvertently omitted from the code implementation. Such memory management errors in kernel space can have significant implications for system stability and resource utilization, particularly in environments where display operations are frequent or intensive.
The technical root cause of this vulnerability lies in the improper handling of display stream resources within the AMD display driver's link management logic. When a display link is removed or reassigned, the system should invoke the dc_stream_release() function to free the associated memory resources that were previously allocated for stream assignment. However, due to the porting error, this cleanup function call was omitted from the code path, resulting in persistent memory allocation that cannot be reclaimed by the system. This memory leak occurs within the drm/amd/display subsystem and specifically affects the dc_stream_release() function call that should have been included as part of the original patch implementation. The vulnerability represents a classic case of resource management failure where allocated kernel memory remains unreleased, leading to gradual memory consumption over time.
The operational impact of this memory leak extends beyond simple resource waste, potentially affecting system performance and stability in scenarios involving frequent display link operations or high-density graphics workloads. While the immediate effect may appear benign in short-term operations, prolonged system usage can lead to progressive memory exhaustion, particularly in embedded systems or servers with limited memory resources. The vulnerability affects systems utilizing AMD graphics hardware through the Linux kernel's display subsystem, making it relevant to desktop environments, servers, and embedded systems that rely on AMD GPU display capabilities. The memory leak could manifest as reduced system responsiveness, increased memory pressure, or in extreme cases, system instability or crashes when memory resources become critically low.
Mitigation strategies for this vulnerability focus primarily on applying the official kernel patch that reintroduces the missing dc_stream_release() function call. System administrators should ensure their Linux kernel installations are updated to versions that include this fix, typically found in kernel releases following the patch implementation. The remediation process involves verifying that the drm/amd/display subsystem properly executes the stream release function during link removal operations, ensuring that all allocated memory resources are correctly returned to the system. Additionally, monitoring system memory usage and display-related kernel operations can help identify potential impacts of this vulnerability in environments where display link management is intensive. This vulnerability aligns with CWE-401, which categorizes memory leaks as a common software weakness, and represents a specific implementation gap in the display driver's resource management that requires careful attention during kernel development and maintenance cycles.