CVE-2024-27421 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_routing_control
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 • 05/19/2026
The vulnerability identified in the Linux kernel represents a critical data-race condition affecting the netrom subsystem's sysctl parameter sysctl_netrom_routing_control. This issue occurs within the network routing framework where concurrent access patterns create potential for inconsistent data states during read and write operations. The vulnerability specifically targets the netrom routing control mechanism that manages network routing decisions for the netrom protocol implementation.
The technical flaw manifests when multiple threads or processes attempt to simultaneously access the sysctl_netrom_routing_control parameter without proper synchronization mechanisms. This race condition allows for a scenario where a reader process may retrieve an inconsistent or partially updated value while another process is modifying the same parameter. The vulnerability stems from inadequate mutex or spinlock protection around the shared data structure controlling routing behavior, creating potential for unpredictable network routing decisions and system instability.
From an operational impact perspective, this data-race condition could lead to severe consequences including network packet loss, routing table corruption, and potential denial of service conditions within systems utilizing netrom networking protocols. The vulnerability affects systems running Linux kernels where netrom functionality is enabled and actively used for network communication. Attackers could potentially exploit this condition to manipulate routing decisions or cause system crashes through carefully timed concurrent access patterns.
The fix implemented addresses this vulnerability by introducing proper synchronization mechanisms around the sysctl_netrom_routing_control parameter access. This typically involves implementing mutex locks or similar atomic operations that ensure exclusive access during parameter reads and writes, preventing concurrent modification scenarios that could lead to data corruption or inconsistent states. The solution aligns with standard security practices for protecting shared resources in multi-threaded environments.
This vulnerability classification maps to CWE-362, which specifically addresses concurrent execution using shared data structures without proper synchronization. The issue also relates to ATT&CK technique T1059 which involves executing malicious code through system-level modifications. The fix demonstrates proper defensive programming practices that align with the principle of least privilege and data integrity protection. The resolution ensures that network routing decisions remain consistent and reliable while maintaining system stability under concurrent access conditions.
Security practitioners should prioritize this patch deployment across systems utilizing netrom networking capabilities, particularly in mission-critical infrastructure where network reliability is paramount. The vulnerability represents a foundational security issue that could potentially be leveraged for broader system compromise if left unaddressed. Organizations should verify kernel versions and ensure proper patch management procedures are in place to prevent exploitation of this concurrent access vulnerability.