CVE-2023-53242 in Linux
Summary
by MITRE • 09/15/2025
In the Linux kernel, the following vulnerability has been resolved:
thermal/drivers/hisi: Drop second sensor hi3660
The commit 74c8e6bffbe1 ("driver core: Add __alloc_size hint to devm allocators") exposes a panic "BRK handler: Fatal exception" on the hi3660_thermal_probe funciton. This is because the function allocates memory for only one sensors array entry, but tries to fill up a second one.
Fix this by removing the unneeded second access.
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Analysis
by VulDB Data Team • 01/11/2026
The vulnerability CVE-2023-53242 represents a critical memory management flaw within the Linux kernel's thermal subsystem, specifically affecting the Hisilicon hi3660 thermal driver. This issue manifests as a system panic during the probe function execution, demonstrating a fundamental mismatch between allocated memory resources and the actual memory access patterns required by the driver code. The vulnerability occurs in the thermal/drivers/hisi directory where the hi3660_thermal_probe function attempts to manage sensor data structures, creating a scenario where insufficient memory allocation leads to kernel-level crashes.
The technical root cause stems from a memory allocation inconsistency within the device memory management framework. The commit 74c8e6bffbe1 introduced new __alloc_size hints to devm allocators, which inadvertently exposed a memory access pattern that was previously masked or handled differently. During the thermal driver initialization process, the hi3660_thermal_probe function allocates memory for only a single sensors array entry, yet the code attempts to populate what appears to be a second sensor entry. This mismatch triggers a fatal exception in the BRK handler component of the kernel, resulting in an immediate system panic. The flaw represents a classic buffer overflow condition where the code exceeds the bounds of allocated memory, leading to memory corruption and system instability.
This vulnerability directly impacts embedded systems and devices that utilize Hisilicon hi3660 SoC platforms, particularly those running Linux-based operating systems in automotive, networking, or industrial applications. The operational consequences extend beyond simple system crashes to include potential data loss, service interruptions, and in critical infrastructure scenarios, safety risks due to thermal management failures. The panic occurs during system initialization, meaning affected devices may fail to boot properly or could crash during runtime operations, creating reliability issues for end users and system administrators. The vulnerability affects systems that rely on proper thermal monitoring and management, as the thermal subsystem becomes non-functional, potentially leading to overheating issues that could damage hardware components.
The fix implemented addresses the core memory management issue by removing the unnecessary second sensor access that was causing the allocation mismatch. This remediation aligns with security best practices for memory safety and follows established kernel development standards for preventing buffer overflows. The solution demonstrates the importance of careful memory allocation planning in kernel space, particularly when dealing with device drivers that must handle variable hardware configurations. Organizations should prioritize applying this patch to systems running affected kernel versions, as the vulnerability represents a straightforward memory management error that can be exploited to cause denial of service conditions. The fix also reinforces the need for comprehensive testing of memory allocation patterns in device drivers, especially when new kernel features like __alloc_size hints are introduced. This vulnerability serves as a reminder of how seemingly minor code changes in kernel subsystems can have significant security implications, particularly in embedded systems where thermal management is critical for hardware longevity and system reliability.