CVE-2023-1855 in Linux
Summary
by MITRE • 04/05/2023
A use-after-free flaw was found in xgene_hwmon_remove in drivers/hwmon/xgene-hwmon.c in the Hardware Monitoring Linux Kernel Driver (xgene-hwmon). This flaw could allow a local attacker to crash the system due to a race problem. This vulnerability could even lead to a kernel information leak problem.
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Analysis
by VulDB Data Team • 06/21/2025
The vulnerability identified as CVE-2023-1855 represents a critical use-after-free flaw within the xgene-hwmon kernel driver, specifically in the xgene_hwmon_remove function located at drivers/hwmon/xgene-hwmon.c. This flaw constitutes a fundamental memory management error that occurs when the kernel attempts to access memory that has already been freed, creating a dangerous condition that can be exploited by local attackers. The vulnerability manifests as a race condition during device removal operations, where the timing of memory deallocation and subsequent access creates an opportunity for malicious code execution.
The technical implementation of this flaw involves improper synchronization mechanisms within the hardware monitoring driver's removal routine, where the driver fails to properly manage reference counting or locking mechanisms during the cleanup process. When a device is removed from the xgene-hwmon subsystem, the kernel attempts to free allocated memory structures while other kernel threads or processes may still be accessing those same structures, leading to undefined behavior. This race condition creates a window where freed memory can be reallocated and accessed, potentially causing system crashes or allowing for more sophisticated exploitation techniques.
From an operational perspective, this vulnerability poses significant risks to system stability and security, particularly in embedded systems or network appliances that rely heavily on hardware monitoring capabilities. The local attacker can leverage this flaw to cause system crashes, potentially leading to denial of service conditions that could disrupt critical operations. The information leak aspect of this vulnerability arises from the possibility that freed memory contents may remain accessible to the attacker, potentially exposing kernel memory structures, sensitive data, or implementation details that could be used to refine exploitation techniques. This vulnerability directly impacts the kernel's memory safety mechanisms and can compromise the integrity of the entire system.
The flaw aligns with CWE-416, which specifically addresses use-after-free vulnerabilities, and demonstrates poor adherence to memory management best practices in kernel space programming. From an attack surface perspective, this vulnerability falls under the ATT&CK technique T1068, which involves exploiting local privileges to gain unauthorized access and execute malicious code within the kernel context. The vulnerability's impact extends beyond simple system crashes to potentially enable privilege escalation or information disclosure attacks, making it a critical concern for system administrators and security professionals. Mitigation strategies should include immediate patching of affected kernel versions, implementation of proper locking mechanisms, and comprehensive monitoring for exploitation attempts. The vulnerability highlights the importance of thorough race condition analysis in kernel drivers and underscores the necessity of rigorous security testing for hardware monitoring components that handle device lifecycle management operations.