CVE-2023-53997 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
thermal: of: fix double-free on unregistration
Since commit 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone parameters structure"), thermal_zone_device_register() allocates a copy of the tzp argument and frees it when unregistering, so thermal_of_zone_register() now ends up leaking its original tzp and double-freeing the tzp copy. Fix this by locating tzp on stack instead.
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Analysis
by VulDB Data Team • 02/25/2026
This vulnerability exists within the linux kernel's thermal management subsystem where a double-free error occurs during the unregistration process of thermal zones. The issue stems from changes made in commit 3d439b1a2ad3 which altered how thermal zone parameters are handled by allocating a copy of the tzp argument during registration and subsequently freeing this copy during unregistration. However, this change created a scenario where the original tzp parameter passed to thermal_of_zone_register() is leaked while simultaneously causing a double-free condition when the copied structure is freed. The flaw manifests when the thermal subsystem attempts to unregister thermal zones, leading to potential memory corruption and system instability.
The technical implementation of this vulnerability involves improper memory management practices within the thermal zone registration and unregistration pathways. When thermal_of_zone_register() is called, it receives a thermal zone parameters structure (tzp) that gets copied during the registration process. The subsequent unregistration logic frees this copied structure but fails to account for the original tzp parameter that should have been properly managed. This creates a classic double-free vulnerability where the same memory location is freed twice, potentially allowing attackers to manipulate memory layout or execute arbitrary code through memory corruption. The vulnerability directly relates to CWE-415 which addresses double free conditions in memory management.
The operational impact of this vulnerability extends across all linux kernel versions affected by the problematic commit, particularly impacting systems with thermal management capabilities such as servers, embedded devices, and mobile platforms. Systems running kernel versions containing the faulty commit may experience kernel panics, system crashes, or memory corruption during thermal zone unregistration events. This could lead to denial of service conditions where thermal management functionality becomes unavailable, potentially causing overheating issues in hardware components. The vulnerability is particularly concerning in server environments where thermal management is critical for system stability and where attackers could exploit the double-free condition to escalate privileges or cause persistent system instability.
Mitigation strategies for this vulnerability require immediate kernel updates to versions that contain the fix for commit 3d439b1a2ad3, which resolves the double-free issue by ensuring that the tzp parameter is properly managed on the stack rather than being allocated and freed inappropriately. System administrators should prioritize patching affected systems and monitor for any signs of kernel panics or thermal management failures following updates. Additionally, implementing memory corruption detection mechanisms and monitoring for unusual memory allocation patterns can help identify potential exploitation attempts. Organizations should also consider implementing runtime protections such as stack canaries or memory sanitization tools to detect and prevent exploitation of similar memory management flaws. The fix aligns with ATT&CK technique T1068 which addresses privilege escalation through kernel exploits, making it a critical vulnerability to address promptly.