CVE-2024-36956 in Linux
Summary
by MITRE • 05/30/2024
In the Linux kernel, the following vulnerability has been resolved:
thermal/debugfs: Free all thermal zone debug memory on zone removal
Because thermal_debug_tz_remove() does not free all memory allocated for thermal zone diagnostics, some of that memory becomes unreachable after freeing the thermal zone's struct thermal_debugfs object.
Address this by making thermal_debug_tz_remove() free all of the memory in question.
Cc :6.8+ # 6.8+
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Analysis
by VulDB Data Team • 10/01/2025
The vulnerability identified as CVE-2024-36956 resides within the Linux kernel's thermal management subsystem, specifically affecting the debugfs interface implementation for thermal zones. This issue represents a memory management flaw that occurs during the cleanup process of thermal zone diagnostic information. The vulnerability manifests when thermal zone debugfs objects are removed from the system, leaving behind allocated memory that cannot be properly reclaimed. Such memory leaks typically occur in kernel space environments where proper resource cleanup is critical for system stability and performance. The affected component operates under the thermal subsystem which is responsible for monitoring and managing temperature conditions across various hardware components in computing systems.
The technical flaw stems from the incomplete memory deallocation within the thermal_debug_tz_remove() function, which is designed to handle the removal of thermal zone debugfs objects. When a thermal zone is removed from the system, this function is responsible for freeing all associated memory resources including diagnostic data structures. However, the current implementation fails to free all memory that was allocated for thermal zone diagnostics, resulting in memory leaks that accumulate over time. This type of memory management error falls under the category of improper deallocation patterns commonly classified as CWE-415, which specifically addresses double free errors and memory leaks in kernel space implementations. The vulnerability becomes particularly problematic in long-running systems where thermal zones may be repeatedly created and destroyed, leading to progressive memory consumption and potential system instability.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as it can lead to system performance degradation and potential resource exhaustion over extended periods of operation. In embedded systems or server environments where thermal management is continuously active, the accumulation of unreclaimed memory can eventually impact system responsiveness and overall resource availability. The vulnerability affects kernel versions 6.8 and later, indicating that it was introduced in recent kernel releases and represents a regression or oversight in the thermal debugging implementation. This type of issue can be particularly concerning in production environments where system uptime is critical, as memory leaks can silently degrade performance without immediate visible symptoms. The vulnerability also poses risks to systems that rely heavily on thermal zone monitoring for power management and system protection mechanisms.
Mitigation strategies for CVE-2024-36956 focus primarily on applying the kernel patch that corrects the memory deallocation logic in the thermal_debug_tz_remove() function. System administrators should prioritize updating to kernel versions that include the fix, which specifically addresses the complete memory cleanup process for thermal zone diagnostics. The patch ensures that all memory allocated for thermal zone debugfs operations is properly freed when zones are removed, preventing the accumulation of unreachable memory segments. Organizations should implement regular kernel update procedures to maintain protection against such vulnerabilities, particularly in environments where thermal management is critical for system operation. Additionally, monitoring system memory usage patterns can help detect potential memory leak symptoms, though the primary defense remains the kernel-level fix. The vulnerability's resolution aligns with ATT&CK technique T1490 which covers resource exhaustion attacks, as memory leaks can contribute to system resource degradation that may be exploited in broader attack scenarios.