CVE-2024-27426 in Linux
Summary
by MITRE • 05/17/2024
In the Linux kernel, the following vulnerability has been resolved:
netrom: Fix a data-race around sysctl_netrom_transport_maximum_tries
We need to protect the reader reading the sysctl value because the value can be changed concurrently.
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Analysis
by VulDB Data Team • 07/21/2025
The vulnerability identified in the Linux kernel represents a critical data-race condition affecting the netrom subsystem's sysctl parameter sysctl_netrom_transport_maximum_tries. This issue arises from insufficient synchronization mechanisms when accessing shared kernel memory locations that store configuration values used by network protocols. The vulnerability specifically impacts the NetROM protocol implementation which is part of the Linux kernel's networking stack designed for amateur radio packet radio networks. When multiple threads or processes attempt to read and modify this particular sysctl parameter simultaneously, the race condition can lead to unpredictable behavior and potential system instability.
The technical flaw manifests as a classic read-modify-write race condition where concurrent access to the sysctl_netrom_transport_maximum_tries variable creates opportunities for inconsistent data states. This occurs because the kernel does not employ proper locking mechanisms or atomic operations when handling reads and writes to this configuration parameter, allowing one thread to observe partially updated values or conflicting states during the transition period between updates. The vulnerability is particularly concerning in multi-threaded environments where network operations might be actively processing while configuration changes are being applied, creating a window where data integrity cannot be guaranteed.
The operational impact of this vulnerability extends beyond simple incorrect parameter values and can potentially compromise the stability and security of network communications within affected systems. When the data-race occurs during critical network operations such as packet transmission or connection establishment, it may result in unpredictable protocol behavior, failed connections, or even system crashes. The vulnerability affects all Linux kernel versions where the NetROM subsystem is present and actively used, making it a widespread concern for systems that rely on amateur radio networking capabilities or embedded devices using this networking protocol.
Mitigation strategies for this vulnerability primarily focus on implementing proper synchronization mechanisms around the sysctl parameter access. The recommended approach involves introducing appropriate locking primitives such as mutexes or spinlocks to protect critical sections when accessing the sysctl_netrom_transport_maximum_tries variable. Additionally, modern kernel programming practices suggest utilizing atomic operations or read-copy-update patterns to ensure thread-safe access without significant performance degradation. This remediation aligns with common security best practices and follows established patterns for concurrent access control in kernel space programming as outlined in various kernel security guidelines and standards.
The vulnerability can be categorized under CWE-362, which specifically addresses race conditions in software development, and demonstrates how improper synchronization mechanisms in kernel code can create exploitable weaknesses. From an attack perspective, while this particular vulnerability may not directly enable privilege escalation or remote code execution, it represents a potential vector for system instability that could be leveraged in denial-of-service scenarios or combined with other vulnerabilities to create more severe impacts within networked environments. The fix implemented by the Linux kernel security team involves adding appropriate locking mechanisms around the sysctl access points, ensuring that concurrent read and write operations are properly serialized to maintain data integrity throughout the system's networking subsystem.
This vulnerability resolution exemplifies the importance of proper synchronization in kernel-level programming and reflects the broader challenges faced by security researchers in identifying and addressing concurrency-related issues. The fix demonstrates adherence to security standards and best practices established in both kernel development communities and cybersecurity frameworks that emphasize the need for robust concurrent access control mechanisms. Systems administrators should prioritize applying the relevant kernel updates to address this vulnerability, particularly in environments where NetROM protocol functionality is actively utilized or where high availability and system stability are critical requirements for network operations.