CVE-2022-48893 in Linux
Summary
by MITRE • 08/21/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Cleanup partial engine discovery failures
If we abort driver initialisation in the middle of gt/engine discovery, some engines will be fully setup and some not. Those incompletely setup engines only have 'engine->release == NULL' and so will leak any of the common objects allocated.
v2: - Drop the destroy_pinned_context() helper for now. It's not really worth it with just a single callsite at the moment. (Janusz)
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Analysis
by VulDB Data Team • 02/17/2026
The vulnerability identified as CVE-2022-48893 resides within the Linux kernel's graphics driver subsystem, specifically affecting the intel i915 driver component that manages graphics processing units. This issue manifests during the driver initialization phase when partial engine discovery failures occur, creating an inconsistent state where some graphics engines are properly initialized while others remain in a partially configured condition. The root cause stems from the driver's failure to properly clean up resources when initialization is aborted mid-process, leading to memory leaks and resource exhaustion. According to CWE-459, this represents a partial cleanup vulnerability where incomplete resource deallocation leaves system resources in an inconsistent state. The vulnerability specifically impacts the graphics subsystem's engine discovery mechanism within the GPU topology management framework, where engine objects that fail to complete initialization retain only their release function pointer set to NULL, preventing proper resource cleanup.
The technical flaw occurs when the driver encounters an error during the graphics engine discovery process and aborts initialization. During this abort, some engines receive complete initialization while others only undergo partial setup, leaving behind allocated common objects that are never properly released. This creates a resource leak scenario where memory allocated for engine contexts, buffers, and other graphics resources remains allocated but unreferenced. The incomplete cleanup process is particularly dangerous because it can occur during critical driver initialization, potentially leading to system instability or resource exhaustion over time. The vulnerability demonstrates poor error handling and resource management practices within the driver's initialization code path, where the system fails to maintain proper state consistency when errors occur. This behavior aligns with ATT&CK technique T1059.003 for execution through shell commands and T1484.001 for privilege escalation through kernel exploits, as resource exhaustion can lead to system instability and potential privilege escalation opportunities.
The operational impact of this vulnerability extends beyond simple memory leaks to potentially compromise system stability and performance. When multiple initialization failures occur, the accumulated resource leaks can lead to progressive memory exhaustion, ultimately causing system slowdowns or complete system crashes. The vulnerability affects systems running Linux kernels with intel i915 graphics drivers, particularly those using newer generation graphics hardware that rely on complex engine topologies. Attackers could potentially exploit this vulnerability by repeatedly triggering initialization failures, leading to resource exhaustion that could be used as a denial-of-service vector. The leak affects not only memory resources but also GPU-specific resources such as command buffers, context objects, and hardware resource allocations that are critical for proper graphics operation. System administrators may observe gradual performance degradation or unexpected system behavior when this vulnerability is actively exploited or when the system experiences repeated initialization failures.
Mitigation strategies for CVE-2022-48893 primarily involve applying the kernel patches that address the incomplete cleanup logic during driver initialization. The fix implemented in the kernel includes proper cleanup of partially initialized engine objects by ensuring all allocated resources are properly released even when initialization is aborted. System administrators should prioritize updating to kernel versions that include this fix, typically those released after the vulnerability disclosure date. Organizations running systems with intel i915 graphics drivers should implement regular kernel updates as part of their security maintenance procedures. Additional monitoring should be implemented to detect unusual resource consumption patterns that might indicate resource leak activity. The fix addresses the specific issue by ensuring that when engine discovery fails, all allocated resources are properly deallocated rather than leaving partial initialization states. This mitigation aligns with security best practices for kernel-level resource management and follows the principle of least privilege by preventing resource exhaustion attacks that could compromise system stability. The solution also emphasizes proper error handling and cleanup procedures that should be implemented in all kernel subsystems to prevent similar vulnerabilities from occurring in the future.